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Proprioception of the Wrist Following Posterior Interosseous Sensory Neurectomy
SCIENTIFIC ARTICLE
Proprioception of the Wrist Following Posterior Interosseous Sensory Neurectomy Ryan W. Patterson, MD, Monica Van Niel, BA, Patty Shimko, BS, Carter Pace, MD, William H. Seitz, Jr, MD Purpose The posterior interosseous sensory nerve innervates the dorsal capsule of the wrist, which may provide nociceptive and proprioceptive sensation. Posterior interosseous sensory neurectomy (PISN) is commonly used as a primary or adjunctive procedure to provide wrist analgesia for a variety of wrist conditions. Currently, there is little information in the literature regarding the proprioceptive role of the posterior interosseous sensory nerve and the resultant effects of PISN on wrist proprioception. The purpose of our investigation was to examine the effect of PISN on wrist proprioception. Methods For 23 consecutive patients who had posterior interosseous sensory neurectomy, proprioception of their surgical wrists was compared to their nonsurgical wrists as well as to the normal wrists of 23 healthy volunteers. Using a custom testing device, wooden dowels were used to set subjects’ wrists at specific angles within the testing jig, and then subjects were asked to mimic the position with their other hand at the following angles: neutral (0°), flexion (20°, 40°, 60°), extension (20°, 40°, 60°), 10° of radial deviation, and 10° of ulnar deviation. The following statistical comparisons were made:1 patients’ surgical versus controls’ assessed wrists and2 patients’ surgical wrists versus patients’ nonsurgical wrists. Results There were no statistically significant differences in wrist proprioception except in 40° of extension with more accurate estimations by surgical wrists when compared to control wrists. Conclusions Posterior interosseous sensory neurectomy does not appear to be associated with decreased proprioception of the wrist as measured by a custom testing device. (J Hand Surg 2010;35A:52–56. Copyright © 2010 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Posterior interosseous nerve, posterior interosseous sensory neurectomy, proprioception, wrist denervation. sensory nerve provides sensation to the dorsal capsule of the wrist. However, the sensory role of the posterior interosseous sensory nerve has not been clearly
T
HE POSTERIOR INTEROSSEOUS
From the Cleveland Clinic, Cleveland, OH; Metrohealth Medical Center, Cleveland, OH; Cleveland Orthopaedic and Spine Hospital, Cleveland, OH. Received for publication May 16, 2009; accepted in revised form October 15, 2009. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: William H. Seitz, Jr., MD, Cleveland Orthopaedic and Spine Hospital, 1730 West 25th Street, Cleveland, OH 44113; e-mail: [email protected]. 0363-5023/10/35A01-0010$36.00/0 doi:10.1016/j.jhsa.2009.10.014
52 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
defined. Because the terminal branches of the posterior interosseous nerve innervate the dorsal wrist capsule, it is thought to provide both nociception and proprioception.1 Posterior interosseous sensory neurectomy (PISN) is commonly used as a primary or adjunctive procedure, to provide wrist analgesia for a variety of wrist conditions. Wrist denervation, as originally described by Wilhelm2 in 1966, has reduced pain in 51% to 69% of patients with arthritis, fractures, and chronic ligamentous injuries.2– 6 Denervation of the wrist joint capsule has reduced pain in a mean of 75% of patients (range, 24% to 90%).2,4,7–18 Dellon6 reported relief of pain in 90% of patients with objective improvements in wrist function, as well as an 83% return-to-work rate in
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
patients with chronic dorsal wrist pain secondary to various etiologies after PISN. Common surgical conditions in which PISN is used include carpal instability, distal radius fractures, distal radioulnar joint pathology, Kienböck’s disease, osteoarthritis, rheumatoid arthritis, scaphoid nonunion advanced collapse, and scapolunate advanced collapse, as well as many other pathologic conditions of the wrist. The PISN has also been described as a source for digital nerve autograft.19 After innervating the extensor pollicis longus, the posterior interosseous nerve sends a branch to the distal radioulnar joint, enters the fourth dorsal extensor compartment, and then arborizes into 3 to 4 smaller branches that spread over the dorsal wrist capsule.17 Ekerot et al.11 reported that the posterior interosseous nerve was the only nerve to be consistently identified in all 48 patients in their series of extensive wrist denervations. Currently, there is little information in the literature regarding the proprioceptive role of the posterior interosseous sensory nerve and the resultant effects of PISN on wrist proprioception. The purpose of our investigation was to examine wrist proprioception after PISN. MATERIALS AND METHODS After institutional review board approval, 23 consecutive patients in which PISN was a part of their wrist surgery were enrolled. Twenty-three volunteers who had no history of wrist symptoms, surgery, or pathology served as controls. Men comprised 83% and 26% of the postoperative and control group, respectively. The mean age of the experimental group was 47 years (range, 26 –75 years), and the mean age of the control group was 34 years (range, 18 –71 years). Fifty-two percent of the postoperative group had surgery on their dominant extremity. Subjects included 8 patients with distal radius fractures (open reduction internal fixation), 6 with scapholunate instability (dorsal capsulodesis), 5 with distal radius malunions (corrective osteotomy), and 4 with scapholunate advanced collapse (limited wrist arthrodesis or proximal row carpectomy). All patients were at least 1 year postsurgical at the time of testing, with sufficient active and passive range of motion in which the angles tested did not cause discomfort. A review of the literature revealed no standardized or validated test or tool to assess wrist proprioception in adults. The authors therefore used the basic test that is recommended in a commonly used occupational therapy textbook.20 In the proprioception test described by
53
FIGURE 1: Custom testing device, consisting of a barrier to obscure the subject’s vision during testing with 2 holes for their hands and wrists. Markings with measured angles and dowel rods were used by the occupational therapists to test wrist proprioception.
this textbook, the tested joint is passively positioned by the occupational therapist, who then asks the subject to mimic this position with their contralateral joint. A custom testing device was developed by occupational therapists (Fig. 1) in which subjects placed both their wrists and hands through openings in a barrier that obscured their vision. Dowel rods in the base board of the device served to guide only the tested wrists into position at the tested angles, and the contralateral wrist was free of any obstruction. During the design of the testing device, the occupational therapists placed their own hands and wrists within the jig and measured the angles of their wrists in flexion and extension with a goniometer. Their wrists entered the device from both sides of the barrier such that when entering from 1 side, the left wrist was tested (as in Fig. 1) and when entering from the opposite side, the right wrist was tested. Next, holes were drilled for the rods in positions dorsal (when wrists were in extension) or volar (when wrists were in flexion) to their extended fingers such that the dowels served as a dorsal (in extension) and volar (in flexion) block at the tested angles. These holes were drilled on both sides of the barrier such that the left wrist could be tested on 1 side of the barrier and the right wrist could be tested on the opposite side. With the dowel rods serving as flexion or extension blocks, the subjects’ wrists were tested in neutral, in positions of 20°, 40°, and 60° of wrist flexion and extension, then in neutral again, and finally in 10° of radial and ulnar deviation. The tested wrist positions in neutral, flexion, and extension were confirmed and adjusted as needed with a goniometer to ensure accurate positioning. Finally, a goniometer was used by the occupational therapist to passively position the tested wrists in 10° radial and ulnar deviation instead of using the dowel rods because
JHS 䉬 Vol A, January
54
TABLE 1:.
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
Patients’ Surgical Versus Controls’ Assessed Wrists NTL
FLX 20°
FLX 40°
FLX 60°
EXT 20°
EXT 40°
EXT 60°
NTL
RD 10°
UD 10°
Patients
⫺1.3
13.4
28.6
45.5
30.0
45.8
59.8
⫺1.3
8.7
16.3
Controls
0.0
14.3
25.2
44.3
32.9
52.2
62.5
0.2
11.8
16.9
t-test
.328
.764
.419
.830
.339
.032*
.226
.113
.367
.829
*Statistically significant (p ⬍ .05); NTL, neutral wrist position; FLX, wrist flexed to corresponding angle (°); EXT, wrist extended to corresponding angle (°); RD, wrist radially deviated to corresponding angle (°); UD, wrist ulnarly deviated corresponding angle (°).
TABLE 2.
Patients’ Surgical Versus Nonsurgical Wrists NTL
Surgical
⫺2.5
FLX 20° 17
Nonsurgical
0
9.4
t-test
0.338
0.121
FLX 40°
FLX 60°
EXT 20°
EXT 40°
EXT 60°
NTL
RD 10°
UD 10° 14
31.4
45
29.6
44.3
59.7
⫺1.3
10.8
25.2
46.3
30.5
47
60
⫺1.4
6.5
0.344
0.915
0.876
0.540
0.918
0.951
0.470
18.7 0.415
*Statistically significant (p ⬍ .05); NTL, neutral wrist position; FLX, wrist flexed to corresponding angle (°); EXT, wrist extended to corresponding angle (°); RD, wrist radially deviated to corresponding angle (°); UD, wrist ulnarly deviated to corresponding angle (°).
holes could not be drilled to accurately test this smaller angle. To test proprioception of the surgical wrists of patients’ who had PISN, the occupational therapist passively positioned them in multiple angles using dowel rods as guides. These angles were confirmed and adjusted as needed with a goniometer. With the patient’s vision occluded by the device, and after the therapist placed the surgical wrist into each position using dowels as guides, the therapist instructed the patient as follows: “Please mimic this position with your other hand.” Subjects then positioned their contralateral (nonsurgical) wrist themselves in an attempt to mimic the exact position of their tested (postoperative) wrist without any obstruction (i.e., no dowel rods) as in Fig. 1, which shows a tested left wrist positioned by the occupational therapist and an unobstructed right wrist attempting to mimic the left wrist. The therapist recorded the degrees of flexion, extension, radial deviation, and ulnar deviation of the contralateral, nonsurgical wrist of the patients with a goniometer. In order to test the proprioception of the nonsurgical wrist of the postPISN cases, this wrist was positioned by the therapist, using the dowels as guides at the tested angles. The patients were then asked to mimic this position with their contralateral (surgical) wrists, which were again measured with a goniometer and recorded. Finally, the therapist randomly selected the wrist to be tested for controls, and administered the test in the same fashion. The following statistical comparisons were made: (1)
patients’ surgical wrists versus controls’ assessed wrists and (2) patients’ surgical wrists versus patients’ nonsurgical wrists. Groups were analyzed and compared with Student’s t-tests to assess for statistically significant differences in means. A power analysis showed that 18 patients in each group would be required to detect a 10° difference in wrist range of motion with an alpha of 0.05 and beta of 0.8. RESULTS The differences in wrist angles estimated by the patients using their surgical wrists and controls whose wrists were randomly assigned by therapists are summarized in Table 1. There were no statistically significant differences between patients and controls in any wrist positions except at 40° of extension. At this position, controls estimated 52° with their contralateral wrists, and postoperative patients had a more accurate measurement of 46° (p ⫽ .032). There were no statistically significant differences when comparing patients’ surgical versus nonsurgical wrists (Table 2). In general, both groups were most accurate at estimating wrist positions at neutral (within 0 –3°) and 60° of extension (within 0 –3°). However, the most imprecise estimations were at 40° of flexion (14 –16° underestimations) and 60° of flexion (14 –16° underestimations). Patients and controls tended to overestimate the amount of ulnar (4 –9°) versus radial (-4° to ⫹2°) deviation.
JHS 䉬 Vol A, January
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
DISCUSSION Proprioception is the sense of body position that occurs both at the conscious and unconscious levels.21 Conscious proprioception is transmitted by the posterior column–medial lemniscal system to the cerebrum, whereas unconscious proprioception is communicated by the dorsal spinocerebellar tract to the cerebellum. In addition to providing information for a balanced posture and gait, proprioception supplies protective sensations for joints as well. Disruption of joint proprioception can be a multifactorial process, with the end result of Charcot arthropathy, as seen in patients with diabetes mellitus.22 In our study, there appears to be no significant association between wrist proprioception and PISN. Furthermore, as tested for the purposes of this study, wrist proprioception does not appear to be extremely accurate in our control group who were without wrist pathology. A denervated joint with reduced proprioception might hypothetically have an increased risk of Charcot arthropathy. The loss of proprioception function might alter joint biomechanics, although there is currently no evidence in the literature to support this claim. Lack of proprioception might be necessary but might not be sufficient to cause a Charcot joint. Several published studies of the results of partial and total wrist denervations have not reported postoperative neurogenic arthropathy.4,8,10,14,23 In a review of 313 patients, of which 30 patients had complete wrist denervation and 195 patients were followed for more than 4 years, Buck-Gramcko4 reported no radiographic evidence of Charcot joints. In several series of partial and extensive wrist denervations with follow-up ranging from 2 to 5 years, no changes resembling Charcot arthropathy were observed.6,10,14,23 In another series, no sensory or functional deficits related to PISN were reported.23 Weinstein et al.8 reported that none of their 19 patients who had partial wrist denervation (anterior and posterior interosseous neurectomies) complained of an altered sense of joint position. However, proprioception was not objectively assessed in their study. Furthermore, Schweizer et al.18 reported a trend in improvement of Disabilities of the Arm, Shoulder, and Hand (DASH) scores (p ⫽ .095) with long-term follow-up (average 10 years) of 71 completely denervated wrists, which supports the observations of other authors4,8,10,14,22 that wrist denervation did not increase the risk of a neuropathic joint. One would expect disability scores to worsen over time with the development of Charcot arthropathy. However, Schweizer et al.18 concluded that the improvements in patients’ Disabilities of the Arm, Shoulder, and Hand scores over time
55
might represent an adaptation of pain perception with avoidance of painful movements that occur with chronic pain. One of the reasons that clinical studies have not reported the development of Charcot arthropathy after PISN or complete wrist denervation may be that the wrist capsule is innervated by multiple nerves.24 These nerves include the posterior interosseous nerve, deep and dorsal branches of the ulnar nerve, superficial radial nerve, lateral antebrachial cutaneous nerve, medial antebrachial cutaneous nerve, palmar cutaneous branch of the median nerve, and anterior interosseous nerve.24 Charcot arthropathy is unlikely to develop after PISN because none of the other branches that innervate the wrist joint are disturbed. Furthermore, proprioception of a joint arises not only from articular nerve branches but also from receptors in the skin and muscle, of which the vast majority are left intact after surgery.24 –32 In his classic article, Moberg31 described his experiments and reviewed previous research demonstrating the substantial contributions of cutaneous afferents to hand proprioception, which might be much more important than joint and muscle afferents. Therefore, Charcot arthropathy is unlikely to develop even after total wrist denervation, given that stretch receptors in the skin play a much more substantial role than do joint and muscle receptors in joint proprioception. The likelihood of a neuropathic joint after partial wrist denervation, as in PISN, might be even more remote. Limitations of this study include poorly matched subjects and controls, including dissimilar gender and age distributions. Although there was adequate power to detect a 10° difference in wrist motion, smaller range of motion differences between groups might have been truly present but could not be demonstrated due to the relatively small sample size. Another potential confounding variable was that postoperative patients might have adaptive changes to their proprioceptive sensation from long-standing wrist pathology and pain, which might have allowed them to accommodate and return to a baseline function. Proprioception during the early postoperative period might be different and possibly worse before any potential adaptive mechanisms arise. Posterior interosseous sensory neurectomy is not associated with diminished wrist proprioception. In both the postoperative patients and the control group without previous wrist surgery or pathology, wrist proprioception seems to be fairly inaccurate. REFERENCES 1. Hagert E, Forsgren S, Liung BO. Differences in the presence of mechanoreceptors and nerve structures between wrist ligaments may
JHS 䉬 Vol A, January
56
2.
3. 4. 5.
6. 7. 8.
9. 10.
11. 12.
13. 14. 15.
16.
17.
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
imply differential roles in wrist stabilization. J Ortho Res 2005;23:757–763. Wilhelm A. Articular denervation and its anatomical foundation. A new therapeutic principle in hand surgery. On the treatment of the later stages of lunatomalacia and navicular pseudarthrosis [in German]. Hefte Unfallheilkd 1966;86:1–109. Ekerot L, Holmberg J, Eiken O. Denervation of the wrist. Scand J Plast Reconstr Surg 1983;17:155–157. Buck-Gramcko D. Denervation of the wrist joint. J Hand Surg 1977;2A:54 – 61. Martini AK, Frank G, Kuster HH. Clinical experience with Wilhelm’s method of wrist joint denervation [in German]. Z Orthop Ihre Grenzgeb 1983;121:767–769. Ishida O, Tsai TM, Atasoy E. Long-term results of denervation of the wrist joint for chronic wrist pain. J Hand Surg 1993;18B:76 – 80. Dellon AL. Partial dorsal wrist denervation: resection of the distal posterior interosseous nerve. J Hand Surg 1985;10A:527–533. Weinstein LP, Berger RA. Analgesic benefit, functional outcome, and patient satisfaction after partial wrist denervation. J Hand Surg 2002;27A:833– 839. Geldmacher J, Legal HR, Brug E. Results of denervation of the wrist and wrist joint by Wilhelm’s method. Hand 1972;4:57–59. Rostlund T, Somnier F, Axelsson R. Denervation of the wrist joint—an alternative in conditions of chronic pain. Acta Orthop Scand 1980;51:609 – 616. Ekerot L, Holmberg J, Eiken O. Denervation of the wrist. Scand J Plast Reconstr Surg 1983;17:155–157. Foucher G, Da Silva JB, Ferreres A. Total denervation of the wrist. Apropos of 50 cases [in French]. Rev Chir Orthop Reparatrice Appar Mot 1992;78:186 –190. Buck-Gramcko D. Wrist denervation procedures in the treatment of Kienböck’s disease. Hand Clin 1993;9:517–520. Ishida O, Tsai TM, Atasoy E. Long-term results of denervation of the wrist joint for chronic wrist pain. J Hand Surg 1993;18B:76 – 80. Grechenig W, Mahring M, Clement HG. Denervation of the radiocarpal joint. A follow-up study in 22 patients. J Bone Joint Surg 1998;80B:504 –507. Foucher G, Long Pretz P, Erhard L. Joint denervation, a simple response to complex problems in hand surgery [in French]. Chirurgie 1998;123:183–188. Ferreres A, Suso S, Ordi J, Llusa M, Ruano D. Wrist denervation. Anatomical considerations. J Hand Surg 1995;20B:761–768.
18. Schweizer A, von Känel O, Kammer E, Meuli-Simmen C. Longterm follow-up evaluation of denervation of the wrist. J Hand Surg 2006;31A:559 –564. 19. Inoue S, Ogino T, Tsutida H. Digital nerve grafting using the terminal branch of posterior interosseous nerve: a report of 3 cases. Hand Surg 2002;7:305–307. 20. Kohlmeyer K. Evaluation of sensory and neuromuscular performance components. In: Neistadt ME, Blesedell Crepeau E, eds. Willard and Spackman’s occupational therapy. 9th ed. Philadelphia: Lippincott, 1998:223–260. 21. Johnson EO, Babis GC, Soultanis KC, Soucacos PN. Functional neuroanatomy of proprioception. J Surg Orthop Adv 2008;17:159 – 164. 22. Frykberg RG, Belczyk R. Epidemiology of the Charcot foot. Clin Podiatr Med Surg 2008;25:17–28. 23. Lluch AL, Beasley RW. Treatment of dysesthesia of the sensory branch of the radial nerve by distal posterior interosseous neurectomy. J Hand Surg 1989;14A:121–124. 24. Van de Pol GJ, Koudstaal MJ, Schuurman AH, Bleys RL. Innervation of the wrist joint and surgical perspectives of denervation. J Hand Surg 2006;31A:28 –34. 25. Burgess PR, Wei JY, Clark FJ, Simon J. Signaling of kinesthetic information by peripheral sensory receptors. Annu Rev Neurosci 1982;5:171–187. 26. Goodwin GM. The sense of limb position and movement. Exercise Sport Sci. Rev. 1976;4:87–124. 27. Goodwin GM, McCloskey DI, Matthews PB. The persistence of appreciable kinesthesia after paralysing joint afferents but preserving muscle afferents. Brain Res 1972;37:326 –329. 28. Matthews PBC. Muscle afferents and kinaesthesia. Br Med Bull 1977;33:137–142. 29. McCloskey DI. Kinesthetic sensibility. Physiol Rev 1978;58:763– 820. 30. Roland PE, Ladegaard-Pedersen H. A quantitative analysis of sensations of tension and of kinaesthesia in man: evidence for a peripherally originating muscular sense and for a sense of effort. Brain 1977;100:671– 692. 31. Moberg E. The role of cutaneous afferents in position sense, kinaesthesia, and motor function of the hand. Brain 1983;106(Pt 1):1–19. 32. Dellon AL. Somatosensory testing & rehabilitation. Bethesda, MD: The American Occupational Therapy Association, 1997:32–36.
JHS 䉬 Vol A, January
Proprioception of the Wrist Following Posterior Interosseous Sensory Neurectomy Ryan W. Patterson, MD, Monica Van Niel, BA, Patty Shimko, BS, Carter Pace, MD, William H. Seitz, Jr, MD Purpose The posterior interosseous sensory nerve innervates the dorsal capsule of the wrist, which may provide nociceptive and proprioceptive sensation. Posterior interosseous sensory neurectomy (PISN) is commonly used as a primary or adjunctive procedure to provide wrist analgesia for a variety of wrist conditions. Currently, there is little information in the literature regarding the proprioceptive role of the posterior interosseous sensory nerve and the resultant effects of PISN on wrist proprioception. The purpose of our investigation was to examine the effect of PISN on wrist proprioception. Methods For 23 consecutive patients who had posterior interosseous sensory neurectomy, proprioception of their surgical wrists was compared to their nonsurgical wrists as well as to the normal wrists of 23 healthy volunteers. Using a custom testing device, wooden dowels were used to set subjects’ wrists at specific angles within the testing jig, and then subjects were asked to mimic the position with their other hand at the following angles: neutral (0°), flexion (20°, 40°, 60°), extension (20°, 40°, 60°), 10° of radial deviation, and 10° of ulnar deviation. The following statistical comparisons were made:1 patients’ surgical versus controls’ assessed wrists and2 patients’ surgical wrists versus patients’ nonsurgical wrists. Results There were no statistically significant differences in wrist proprioception except in 40° of extension with more accurate estimations by surgical wrists when compared to control wrists. Conclusions Posterior interosseous sensory neurectomy does not appear to be associated with decreased proprioception of the wrist as measured by a custom testing device. (J Hand Surg 2010;35A:52–56. Copyright © 2010 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Posterior interosseous nerve, posterior interosseous sensory neurectomy, proprioception, wrist denervation. sensory nerve provides sensation to the dorsal capsule of the wrist. However, the sensory role of the posterior interosseous sensory nerve has not been clearly
T
HE POSTERIOR INTEROSSEOUS
From the Cleveland Clinic, Cleveland, OH; Metrohealth Medical Center, Cleveland, OH; Cleveland Orthopaedic and Spine Hospital, Cleveland, OH. Received for publication May 16, 2009; accepted in revised form October 15, 2009. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: William H. Seitz, Jr., MD, Cleveland Orthopaedic and Spine Hospital, 1730 West 25th Street, Cleveland, OH 44113; e-mail: [email protected]. 0363-5023/10/35A01-0010$36.00/0 doi:10.1016/j.jhsa.2009.10.014
52 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
defined. Because the terminal branches of the posterior interosseous nerve innervate the dorsal wrist capsule, it is thought to provide both nociception and proprioception.1 Posterior interosseous sensory neurectomy (PISN) is commonly used as a primary or adjunctive procedure, to provide wrist analgesia for a variety of wrist conditions. Wrist denervation, as originally described by Wilhelm2 in 1966, has reduced pain in 51% to 69% of patients with arthritis, fractures, and chronic ligamentous injuries.2– 6 Denervation of the wrist joint capsule has reduced pain in a mean of 75% of patients (range, 24% to 90%).2,4,7–18 Dellon6 reported relief of pain in 90% of patients with objective improvements in wrist function, as well as an 83% return-to-work rate in
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
patients with chronic dorsal wrist pain secondary to various etiologies after PISN. Common surgical conditions in which PISN is used include carpal instability, distal radius fractures, distal radioulnar joint pathology, Kienböck’s disease, osteoarthritis, rheumatoid arthritis, scaphoid nonunion advanced collapse, and scapolunate advanced collapse, as well as many other pathologic conditions of the wrist. The PISN has also been described as a source for digital nerve autograft.19 After innervating the extensor pollicis longus, the posterior interosseous nerve sends a branch to the distal radioulnar joint, enters the fourth dorsal extensor compartment, and then arborizes into 3 to 4 smaller branches that spread over the dorsal wrist capsule.17 Ekerot et al.11 reported that the posterior interosseous nerve was the only nerve to be consistently identified in all 48 patients in their series of extensive wrist denervations. Currently, there is little information in the literature regarding the proprioceptive role of the posterior interosseous sensory nerve and the resultant effects of PISN on wrist proprioception. The purpose of our investigation was to examine wrist proprioception after PISN. MATERIALS AND METHODS After institutional review board approval, 23 consecutive patients in which PISN was a part of their wrist surgery were enrolled. Twenty-three volunteers who had no history of wrist symptoms, surgery, or pathology served as controls. Men comprised 83% and 26% of the postoperative and control group, respectively. The mean age of the experimental group was 47 years (range, 26 –75 years), and the mean age of the control group was 34 years (range, 18 –71 years). Fifty-two percent of the postoperative group had surgery on their dominant extremity. Subjects included 8 patients with distal radius fractures (open reduction internal fixation), 6 with scapholunate instability (dorsal capsulodesis), 5 with distal radius malunions (corrective osteotomy), and 4 with scapholunate advanced collapse (limited wrist arthrodesis or proximal row carpectomy). All patients were at least 1 year postsurgical at the time of testing, with sufficient active and passive range of motion in which the angles tested did not cause discomfort. A review of the literature revealed no standardized or validated test or tool to assess wrist proprioception in adults. The authors therefore used the basic test that is recommended in a commonly used occupational therapy textbook.20 In the proprioception test described by
53
FIGURE 1: Custom testing device, consisting of a barrier to obscure the subject’s vision during testing with 2 holes for their hands and wrists. Markings with measured angles and dowel rods were used by the occupational therapists to test wrist proprioception.
this textbook, the tested joint is passively positioned by the occupational therapist, who then asks the subject to mimic this position with their contralateral joint. A custom testing device was developed by occupational therapists (Fig. 1) in which subjects placed both their wrists and hands through openings in a barrier that obscured their vision. Dowel rods in the base board of the device served to guide only the tested wrists into position at the tested angles, and the contralateral wrist was free of any obstruction. During the design of the testing device, the occupational therapists placed their own hands and wrists within the jig and measured the angles of their wrists in flexion and extension with a goniometer. Their wrists entered the device from both sides of the barrier such that when entering from 1 side, the left wrist was tested (as in Fig. 1) and when entering from the opposite side, the right wrist was tested. Next, holes were drilled for the rods in positions dorsal (when wrists were in extension) or volar (when wrists were in flexion) to their extended fingers such that the dowels served as a dorsal (in extension) and volar (in flexion) block at the tested angles. These holes were drilled on both sides of the barrier such that the left wrist could be tested on 1 side of the barrier and the right wrist could be tested on the opposite side. With the dowel rods serving as flexion or extension blocks, the subjects’ wrists were tested in neutral, in positions of 20°, 40°, and 60° of wrist flexion and extension, then in neutral again, and finally in 10° of radial and ulnar deviation. The tested wrist positions in neutral, flexion, and extension were confirmed and adjusted as needed with a goniometer to ensure accurate positioning. Finally, a goniometer was used by the occupational therapist to passively position the tested wrists in 10° radial and ulnar deviation instead of using the dowel rods because
JHS 䉬 Vol A, January
54
TABLE 1:.
PROPRIOCEPTION OF THE WRIST FOLLOWING PISN
Patients’ Surgical Versus Controls’ Assessed Wrists NTL
FLX 20°
FLX 40°
FLX 60°
EXT 20°
EXT 40°
EXT 60°
NTL
RD 10°
UD 10°
Patients
⫺1.3
13.4
28.6
45.5
30.0
45.8
59.8
⫺1.3
8.7
16.3
Controls
0.0
14.3
25.2
44.3
32.9
52.2
62.5
0.2
11.8
16.9
t-test
.328
.764
.419
.830
.339
.032*
.226
.113
.367
.829
*Statistically significant (p ⬍ .05); NTL, neutral wrist position; FLX, wrist flexed to corresponding angle (°); EXT, wrist extended to corresponding angle (°); RD, wrist radially deviated to corresponding angle (°); UD, wrist ulnarly deviated corresponding angle (°).
TABLE 2.
Patients’ Surgical Versus Nonsurgical Wrists NTL
Surgical
⫺2.5
FLX 20° 17
Nonsurgical
0
9.4
t-test
0.338
0.121
FLX 40°
FLX 60°
EXT 20°
EXT 40°
EXT 60°
NTL
RD 10°
UD 10° 14
31.4
45
29.6
44.3
59.7
⫺1.3
10.8
25.2
46.3
30.5
47
60
⫺1.4
6.5
0.344
0.915
0.876
0.540
0.918
0.951
0.470
18.7 0.415
*Statistically significant (p ⬍ .05); NTL, neutral wrist position; FLX, wrist flexed to corresponding angle (°); EXT, wrist extended to corresponding angle (°); RD, wrist radially deviated to corresponding angle (°); UD, wrist ulnarly deviated to corresponding angle (°).
holes could not be drilled to accurately test this smaller angle. To test proprioception of the surgical wrists of patients’ who had PISN, the occupational therapist passively positioned them in multiple angles using dowel rods as guides. These angles were confirmed and adjusted as needed with a goniometer. With the patient’s vision occluded by the device, and after the therapist placed the surgical wrist into each position using dowels as guides, the therapist instructed the patient as follows: “Please mimic this position with your other hand.” Subjects then positioned their contralateral (nonsurgical) wrist themselves in an attempt to mimic the exact position of their tested (postoperative) wrist without any obstruction (i.e., no dowel rods) as in Fig. 1, which shows a tested left wrist positioned by the occupational therapist and an unobstructed right wrist attempting to mimic the left wrist. The therapist recorded the degrees of flexion, extension, radial deviation, and ulnar deviation of the contralateral, nonsurgical wrist of the patients with a goniometer. In order to test the proprioception of the nonsurgical wrist of the postPISN cases, this wrist was positioned by the therapist, using the dowels as guides at the tested angles. The patients were then asked to mimic this position with their contralateral (surgical) wrists, which were again measured with a goniometer and recorded. Finally, the therapist randomly selected the wrist to be tested for controls, and administered the test in the same fashion. The following statistical comparisons were made: (1)
patients’ surgical wrists versus controls’ assessed wrists and (2) patients’ surgical wrists versus patients’ nonsurgical wrists. Groups were analyzed and compared with Student’s t-tests to assess for statistically significant differences in means. A power analysis showed that 18 patients in each group would be required to detect a 10° difference in wrist range of motion with an alpha of 0.05 and beta of 0.8. RESULTS The differences in wrist angles estimated by the patients using their surgical wrists and controls whose wrists were randomly assigned by therapists are summarized in Table 1. There were no statistically significant differences between patients and controls in any wrist positions except at 40° of extension. At this position, controls estimated 52° with their contralateral wrists, and postoperative patients had a more accurate measurement of 46° (p ⫽ .032). There were no statistically significant differences when comparing patients’ surgical versus nonsurgical wrists (Table 2). In general, both groups were most accurate at estimating wrist positions at neutral (within 0 –3°) and 60° of extension (within 0 –3°). However, the most imprecise estimations were at 40° of flexion (14 –16° underestimations) and 60° of flexion (14 –16° underestimations). Patients and controls tended to overestimate the amount of ulnar (4 –9°) versus radial (-4° to ⫹2°) deviation.
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DISCUSSION Proprioception is the sense of body position that occurs both at the conscious and unconscious levels.21 Conscious proprioception is transmitted by the posterior column–medial lemniscal system to the cerebrum, whereas unconscious proprioception is communicated by the dorsal spinocerebellar tract to the cerebellum. In addition to providing information for a balanced posture and gait, proprioception supplies protective sensations for joints as well. Disruption of joint proprioception can be a multifactorial process, with the end result of Charcot arthropathy, as seen in patients with diabetes mellitus.22 In our study, there appears to be no significant association between wrist proprioception and PISN. Furthermore, as tested for the purposes of this study, wrist proprioception does not appear to be extremely accurate in our control group who were without wrist pathology. A denervated joint with reduced proprioception might hypothetically have an increased risk of Charcot arthropathy. The loss of proprioception function might alter joint biomechanics, although there is currently no evidence in the literature to support this claim. Lack of proprioception might be necessary but might not be sufficient to cause a Charcot joint. Several published studies of the results of partial and total wrist denervations have not reported postoperative neurogenic arthropathy.4,8,10,14,23 In a review of 313 patients, of which 30 patients had complete wrist denervation and 195 patients were followed for more than 4 years, Buck-Gramcko4 reported no radiographic evidence of Charcot joints. In several series of partial and extensive wrist denervations with follow-up ranging from 2 to 5 years, no changes resembling Charcot arthropathy were observed.6,10,14,23 In another series, no sensory or functional deficits related to PISN were reported.23 Weinstein et al.8 reported that none of their 19 patients who had partial wrist denervation (anterior and posterior interosseous neurectomies) complained of an altered sense of joint position. However, proprioception was not objectively assessed in their study. Furthermore, Schweizer et al.18 reported a trend in improvement of Disabilities of the Arm, Shoulder, and Hand (DASH) scores (p ⫽ .095) with long-term follow-up (average 10 years) of 71 completely denervated wrists, which supports the observations of other authors4,8,10,14,22 that wrist denervation did not increase the risk of a neuropathic joint. One would expect disability scores to worsen over time with the development of Charcot arthropathy. However, Schweizer et al.18 concluded that the improvements in patients’ Disabilities of the Arm, Shoulder, and Hand scores over time
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might represent an adaptation of pain perception with avoidance of painful movements that occur with chronic pain. One of the reasons that clinical studies have not reported the development of Charcot arthropathy after PISN or complete wrist denervation may be that the wrist capsule is innervated by multiple nerves.24 These nerves include the posterior interosseous nerve, deep and dorsal branches of the ulnar nerve, superficial radial nerve, lateral antebrachial cutaneous nerve, medial antebrachial cutaneous nerve, palmar cutaneous branch of the median nerve, and anterior interosseous nerve.24 Charcot arthropathy is unlikely to develop after PISN because none of the other branches that innervate the wrist joint are disturbed. Furthermore, proprioception of a joint arises not only from articular nerve branches but also from receptors in the skin and muscle, of which the vast majority are left intact after surgery.24 –32 In his classic article, Moberg31 described his experiments and reviewed previous research demonstrating the substantial contributions of cutaneous afferents to hand proprioception, which might be much more important than joint and muscle afferents. Therefore, Charcot arthropathy is unlikely to develop even after total wrist denervation, given that stretch receptors in the skin play a much more substantial role than do joint and muscle receptors in joint proprioception. The likelihood of a neuropathic joint after partial wrist denervation, as in PISN, might be even more remote. Limitations of this study include poorly matched subjects and controls, including dissimilar gender and age distributions. Although there was adequate power to detect a 10° difference in wrist motion, smaller range of motion differences between groups might have been truly present but could not be demonstrated due to the relatively small sample size. Another potential confounding variable was that postoperative patients might have adaptive changes to their proprioceptive sensation from long-standing wrist pathology and pain, which might have allowed them to accommodate and return to a baseline function. Proprioception during the early postoperative period might be different and possibly worse before any potential adaptive mechanisms arise. Posterior interosseous sensory neurectomy is not associated with diminished wrist proprioception. In both the postoperative patients and the control group without previous wrist surgery or pathology, wrist proprioception seems to be fairly inaccurate. REFERENCES 1. Hagert E, Forsgren S, Liung BO. Differences in the presence of mechanoreceptors and nerve structures between wrist ligaments may
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imply differential roles in wrist stabilization. J Ortho Res 2005;23:757–763. Wilhelm A. Articular denervation and its anatomical foundation. A new therapeutic principle in hand surgery. On the treatment of the later stages of lunatomalacia and navicular pseudarthrosis [in German]. Hefte Unfallheilkd 1966;86:1–109. Ekerot L, Holmberg J, Eiken O. Denervation of the wrist. Scand J Plast Reconstr Surg 1983;17:155–157. Buck-Gramcko D. Denervation of the wrist joint. J Hand Surg 1977;2A:54 – 61. Martini AK, Frank G, Kuster HH. Clinical experience with Wilhelm’s method of wrist joint denervation [in German]. Z Orthop Ihre Grenzgeb 1983;121:767–769. Ishida O, Tsai TM, Atasoy E. Long-term results of denervation of the wrist joint for chronic wrist pain. J Hand Surg 1993;18B:76 – 80. Dellon AL. Partial dorsal wrist denervation: resection of the distal posterior interosseous nerve. J Hand Surg 1985;10A:527–533. Weinstein LP, Berger RA. Analgesic benefit, functional outcome, and patient satisfaction after partial wrist denervation. J Hand Surg 2002;27A:833– 839. Geldmacher J, Legal HR, Brug E. Results of denervation of the wrist and wrist joint by Wilhelm’s method. Hand 1972;4:57–59. Rostlund T, Somnier F, Axelsson R. Denervation of the wrist joint—an alternative in conditions of chronic pain. Acta Orthop Scand 1980;51:609 – 616. Ekerot L, Holmberg J, Eiken O. Denervation of the wrist. Scand J Plast Reconstr Surg 1983;17:155–157. Foucher G, Da Silva JB, Ferreres A. Total denervation of the wrist. Apropos of 50 cases [in French]. Rev Chir Orthop Reparatrice Appar Mot 1992;78:186 –190. Buck-Gramcko D. Wrist denervation procedures in the treatment of Kienböck’s disease. Hand Clin 1993;9:517–520. Ishida O, Tsai TM, Atasoy E. Long-term results of denervation of the wrist joint for chronic wrist pain. J Hand Surg 1993;18B:76 – 80. Grechenig W, Mahring M, Clement HG. Denervation of the radiocarpal joint. A follow-up study in 22 patients. J Bone Joint Surg 1998;80B:504 –507. Foucher G, Long Pretz P, Erhard L. Joint denervation, a simple response to complex problems in hand surgery [in French]. Chirurgie 1998;123:183–188. Ferreres A, Suso S, Ordi J, Llusa M, Ruano D. Wrist denervation. Anatomical considerations. J Hand Surg 1995;20B:761–768.
18. Schweizer A, von Känel O, Kammer E, Meuli-Simmen C. Longterm follow-up evaluation of denervation of the wrist. J Hand Surg 2006;31A:559 –564. 19. Inoue S, Ogino T, Tsutida H. Digital nerve grafting using the terminal branch of posterior interosseous nerve: a report of 3 cases. Hand Surg 2002;7:305–307. 20. Kohlmeyer K. Evaluation of sensory and neuromuscular performance components. In: Neistadt ME, Blesedell Crepeau E, eds. Willard and Spackman’s occupational therapy. 9th ed. Philadelphia: Lippincott, 1998:223–260. 21. Johnson EO, Babis GC, Soultanis KC, Soucacos PN. Functional neuroanatomy of proprioception. J Surg Orthop Adv 2008;17:159 – 164. 22. Frykberg RG, Belczyk R. Epidemiology of the Charcot foot. Clin Podiatr Med Surg 2008;25:17–28. 23. Lluch AL, Beasley RW. Treatment of dysesthesia of the sensory branch of the radial nerve by distal posterior interosseous neurectomy. J Hand Surg 1989;14A:121–124. 24. Van de Pol GJ, Koudstaal MJ, Schuurman AH, Bleys RL. Innervation of the wrist joint and surgical perspectives of denervation. J Hand Surg 2006;31A:28 –34. 25. Burgess PR, Wei JY, Clark FJ, Simon J. Signaling of kinesthetic information by peripheral sensory receptors. Annu Rev Neurosci 1982;5:171–187. 26. Goodwin GM. The sense of limb position and movement. Exercise Sport Sci. Rev. 1976;4:87–124. 27. Goodwin GM, McCloskey DI, Matthews PB. The persistence of appreciable kinesthesia after paralysing joint afferents but preserving muscle afferents. Brain Res 1972;37:326 –329. 28. Matthews PBC. Muscle afferents and kinaesthesia. Br Med Bull 1977;33:137–142. 29. McCloskey DI. Kinesthetic sensibility. Physiol Rev 1978;58:763– 820. 30. Roland PE, Ladegaard-Pedersen H. A quantitative analysis of sensations of tension and of kinaesthesia in man: evidence for a peripherally originating muscular sense and for a sense of effort. Brain 1977;100:671– 692. 31. Moberg E. The role of cutaneous afferents in position sense, kinaesthesia, and motor function of the hand. Brain 1983;106(Pt 1):1–19. 32. Dellon AL. Somatosensory testing & rehabilitation. Bethesda, MD: The American Occupational Therapy Association, 1997:32–36.
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