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Arthroscopic Ulnar Nerve Decompression in the Setting of Elbow Osteoarthritis
SCIENTIFIC ARTICLE
Arthroscopic Ulnar Nerve Decompression in the Setting of Elbow Osteoarthritis Rudy Kovachevich, MD, Scott P. Steinmann, MD
Purpose To present the technique and outcomes of arthroscopic ulnar nerve decompression at the elbow in a series of patients with associated osteoarthritis. Methods A retrospective chart review identified all patients with symptomatic ulnar compression neuropathy and osteoarthritis at the elbow treated with arthroscopic decompression between March 2002 and June 2007. Information regarding preoperative symptom severity and function, associated arthritis and other disorders of the involved extremity, postoperative symptoms and function, complications, and reoperations were reviewed from the medical record. All patients were followed up for at least 12 months, and data collection included clinical evaluations and survey correspondence. Results Thirteen patients (15 elbows) were available for review. The series consisted of patients with an average age of 51 years (range, 20 –75 y). All patients had arthroscopic ulnar nerve decompression, osteophyte resection, and capsulectomy during the same procedure. An average postoperative follow-up of 47 months revealed 7 excellent, 5 good, 1 fair, and 2 poor results. Three patients had reoperations because of persistent or recurrent symptoms. These 3 patients had severe (Dellon classification) symptoms including muscular wasting on presentation. Conclusions This technique appears to be a useful procedure for treatment of cubital tunnel syndrome at the time of elbow arthroscopic debridement arthroplasty. Additional follow-up and prospective comparative studies are indicated to further evaluate this technique. (J Hand Surg 2012;37A:663–668. Copyright © 2012 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Decompression, elbow arthroscopy, elbow osteoarthritis, ulnar nerve, ulnar neuropathy.
T
HE SUPERFICIAL POSITION of the ulnar nerve at the
cubital tunnel combined with increased intraneural pressure and decreased cubital tunnel volume with elbow flexion make the nerve susceptible to
From the Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN. Received for publication November 18, 2010; accepted in revised form January 5, 2012. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Scott P. Steinmann, MD, Mayo Clinic, Department of Orthopedic Surgery, 200 First Street SW, Rochester, MN 55905; e-mail: [email protected]. 0363-5023/12/37A04-0004$36.00/0 doi:10.1016/j.jhsa.2012.01.003
compression. Gelberman et al1 demonstrated this dynamic phenomenon in a cadaver with a decreased cross-sectional area of up to 50% and an increased intraneural pressure up to 45% from full extension to 130° of flexion. When cubital tunnel syndrome is present in the setting of associated elbow arthritis, some authors have hypothesized the primary cause to be degenerative osteophytes on the medial ridge of the olecranon and trochlea anterior and lateral to the ulnar nerve.2 Mild to moderate ulnar neuropathy with or without associated elbow osteoarthritis can be successfully treated with nonsurgical management. However, patients who fail nonsurgical measures might require surgical treatment.3–9
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Controversy exists over the optimal technique for decompression of the ulnar nerve. Standard surgical approaches include open in situ decompression,10 medial epicondylectomy,11 subcutaneous transposition,12 intramuscular transposition,13 and submuscular transposition.14 Newer techniques using endoscopic or minimally invasive procedures have been described.15–19 In patients with symptomatic elbow osteoarthritis and associated cubital tunnel syndrome having arthroscopic debridement, the ulnar nerve is typically decompressed as a separate open or percutaneous procedure.20 –21 An alternative to these procedures is arthroscopic decompression performed at the time of osteophyte resection and capsulotomy. The purpose of this study was to present the technique and evaluate the results of arthroscopic ulnar nerve decompression in a series of patients with associated osteoarthritis. METHODS Patients Patients with elbow osteoarthritis and concomitant cubital tunnel syndrome treated with arthroscopic ulnar nerve decompression between March 2002 and June 2007 were eligible for the study. Further inclusion criteria included failure of a 6-month trial of nonsurgical management consisting of activity modification, nonsteroidal anti-inflammatory medication, use of an elbow pad, and use of a night extension splint. Exclusion criteria included less than 12 months of clinical followup, preoperative diagnosis of inflammatory or posttraumatic arthritis, or previous elbow surgery. Fifteen elbows in 13 patients were included for analysis in this study, which was approved by our institutional review board. The average age of patients in the study was 51 years (range, 20 –75 y). There were 12 men (92%) and 1 woman (8%). The procedure was performed on 9 right elbows and 6 left elbows. Nine elbows were on the dominant side. Preoperative patient characteristics are documented in Table 1. All patients complaining of pain, numbness, or paresthesias in the distribution of the ulnar nerve were examined for range of motion, 2-point discrimination, grip strength, opposition pinch strength, interosseous muscle strength, and various provocative maneuvers such as Tinel nerve percussion test, direct nerve compression, and elbow flexion. We also recorded clinical presence of intrinsic muscle wasting. The diagnosis of cubital tunnel syndrome was supported by positive nerve conduction/electrodiagnostic studies in 13 of 15 patients. Studies were performed at the authors’ institution and standardized. All studies revealed chronic
focal slowing of nerve conduction in the ulnar nerve segment crossing the elbow. Mild involvement meant focal nerve conduction slowing, normal sensory amplitudes, and no fibrillations. Moderate involvement showed focal conduction slowing with decreased sensory amplitude and some evidence of denervation on needle EMG. Severe changes showed prominent axonal loss (ie, noteworthy loss of motor amplitude on nerve conduction study) with fibrillations and loss of motor units evident on EMG. Information regarding preoperative symptom severity and function were recorded. The 3-stage Dellon classification22 was used to categorize the patients by stage of cubital tunnel syndrome. Five elbows (33%) were classified as mild, 4 (27%) as moderate, and 6 (40%) as severe. The presence and severity of elbow osteoarthritis on plain radiographs were documented for all patients. Preoperative radiographs showed osteophytes involving the tip of the olecranon and the coronoid process and ossification of the olecranon fossa in all elbows. Four elbows (27%) had substantial narrowing of the ulnohumeral articulation, but none had a complete loss of the articular space. Some degree of radiocapitellar osteoarthrosis was present in 9 elbows (60%). After surgery, ulnar nerve function was assessed using the modified Bishop rating system.23 Outcome measures in this system focus on the severity of residual symptoms, symptom improvement, postoperative work status, postoperative grip strength, and postoperative static 2-point discrimination. Residual symptoms included persistence of paresthesias and weakness noted on grip and pinch strength testing. Elbow range of motion after arthroscopic osteophyte debridement was also documented. Surgical technique The patient is placed in the lateral decubitus position for standard elbow arthroscopy. A sterile arm tourniquet is placed on the upper arm and inflated before the start of the procedure. A standard posterolateral portal is established as the arthroscopic viewing portal. From this position, a view is gained across the olecranon fossa, and this can be followed down the medial gutter of the joint. A direct posterior portal is established through the triceps, and, through this portal, an arthroscopic shaver is used to debride the posterior fat pad and gain a view of the posteromedial aspect of the elbow joint. A radiofrequency probe can also be used to debride synovium. The initial goal of the procedure is to clear the posteromedial aspect of the joint to obtain excellent visualization of the posteromedial capsule and medial gutter. A retractor can also be placed through an additional prox-
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TABLE 1.
Summary of Preoperative Patient Characteristics
Gender
Age
Side
1
F
42
Right
Right
Pharmaceutical sales
Mild
Normal
22
3.5
5
2
M
37
Right
Right
Laborer/landscaping
Mild
Normal
44
4.2
3
M
44
Left
Right
Roofing/construction
Mild
Mild
33
3.9
4
M
41
Left
Right
Forklift driver
Moderate
Severe
29
5.0
5
M
73
Right
Right
Semiretired construction foreman
Severe
Severe
36
10.0
6
M
75
Left
Right
Construction
Severe
Moderate
30
6.3
12
5–135
7
M
75
Right
Right
Pipefitter
Severe
Severe
17
3.0
10
15–135
Moderate
8
M
42
Right
Right
Industrial arts teacher
Severe
Moderate
48
8.7
9
25–120
Moderate
9
M
61
Left
Right
Rancher
Severe
Severe
30
1.5
8
10–130
Mild
10
M
62
Right
Right
Rancher
Severe
Severe
43
3.5
8
5–135
Mild
11
M
52
Right
Right
Pipefitter
Moderate
Mild
45
8.2
6
25–120
Severe
12
M
47
Right
Right
FBI agent
Mild
Mild
55
12.0
5
15–130
Mild
13
M
55
Right
Right
Salesman
Moderate
Moderate
46
7.2
7
15–140
Mild
14
M
55
Left
Right
Salesman
Moderate
Mild
48
10.5
6
15–140
Mild
15
M
74
Left
Right
Engineer
Mild
Mild
32
10.0
6
5–135
Mild
EMG
Grip Strength (kg)
Opposition Pinch Strength (kg)
Range of Motion (°)
Osteoarthritis
10–140
Mild
5
5–140
Mild
5
30–115
Mild
7
5–135
Mild
⬎15
20–135
Moderate
Mild
ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
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Case
Occupation
Dellon Classification
Two-Point Discrimination* (mm)
Hand Dominance
*Two-point discrimination measurements are an average of readings from the distal ulnar ring finger, radial small finger, and ulnar small finger.
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TABLE 2.
Summary of Postoperative Findings
Case
Follow-up (mo)
Modified Bishop Score
Grip Strength (kg)
Opposition Pinch Strength (kg)
Two-Point Discrimination* (mm)
Elbow Range of Motion (°)
1
28
Excellent
30
6.9
4
0–140
2
40
Good
48
10.0
4
0–140
3
68
Excellent
52
6.5
5
15–125
4
64
Poor
36
4.4
7
0–135
5
19
Good
45
12.0
9
15–135
6
48
Poor
34
7.4
9
5–135
7
56
Poor
18
3.6
8
5–135
8
14
Good
57
10.3
5
15–125
9
72
Excellent
44
4.3
5
5–130
10
64
Excellent
50
5.2
5
0–135
11
53
Fair
48
8.8
6
15–125
12
24
Excellent
65
14.4
5
5–130
13
58
Excellent
52
9.0
4
10–140
14
55
Good
50
10.5
6
10–140
15
69
Excellent
40
12.2
5
5–135
*Two-point discrimination measurements are an average of readings from the distal ulnar ring finger, radial small finger, and ulnar small finger.
imal portal to aid in visualization of the medial gutter. After adequate space is obtained and the posteromedial capsule is well visualized, a smooth biter is brought into the joint through the direct posterior portal while viewing from the posterolateral portal. The posteromedial capsule is carefully resected, with the biter close to the humerus. The ulnar nerve should be visualized just behind the posteromedial capsule. It is not recommended to use a shaver at this point of the procedure. The posteromedial capsule is removed in a proximal to distal direction starting 3 to 4 cm proximal to the medial epicondyle. Resection of the capsule is continued down to the level of the posterior aspect of the anterior band of the medial collateral ligament. The ulnar nerve is progressively visualized and dissected free from the underlying soft tissue. At this point, the ulnar nerve is checked to ensure its release from proximal to the medial epicondyle to the posterior edge of the medial collateral ligament and to ensure that the entire posteromedial capsule has been resected. As the elbow is flexed and the more superficial structures, including the Osborne ligament, that compress the nerve are encountered, the nerve should be free enough to move away laterally toward the joint. After surgery, a standard bulky posterior plaster splint is applied. The splint is removed on the second postoperative day, and the patient is encouraged to begin full range-of-motion activities.
RESULTS In this series, 13 consecutive patients (15 elbows) were followed up for an average of 47 months (range, 14 – 69 mo). Using the modified Bishop rating system, 7 (47%) patients had excellent results, and 5 (33%) had good results. Fair and poor results were found in 1 and 2 patients, respectively (Table 2). Improvement of paresthesias was noted in 13 of 15 elbows (87%), with the remaining 2 patients having no change in their symptoms. Work status examination showed that 11 (85%) patients returned to their previous level of employment within 4 weeks, with the remaining 2 patients changing occupations due to mild to moderate continued impairment directly related to their ulnar nerve symptoms. No transient or permanent neurological complications were noted. No minor complications such as superficial wound infection, hematoma, or persistent portal site drainage were present. Reoperation occurred in 3 patients, 2 of whom had subsequent open subcutaneous transpositions and one who had open in situ decompression. The 2 patients who had ulnar nerve transpositions had advanced disease (Dellon classification, severe) with intrinsic muscle wasting. Neither patient improved after this second procedure. The final patient had minor improvement with arthroscopic decompression but chose to have open in situ decompression due to continued moderate symptoms. An anconeus ep-
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ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
itrochlearis muscle was found and released. The patient had mild improvement in his ulnar nerve symptoms. DISCUSSION This study reviews the treatment results of arthroscopic cubital tunnel release in patients with associated elbow osteoarthritis. We report that the vast majority (87%) of patients had improvement in paresthesias after surgery, with 80% showing excellent to good results according to the modified Bishop rating system, which is based on objective and subjective criteria as well as on work status. Numerous studies describing new, minimally invasive decompression techniques have been published in recent years and have shown positive results, although none of these studies looked specifically at patients with concomitant arthritis.15,19,24 Tsai et al15 reviewed 76 patients who they treated with a minimally invasive technique involving custom-made grooved glass tubes and a Smillie knife. They found 87% good to excellent results using the modified Bishop rating system and noted minimal complications. Hoffman and Siemionow19 demonstrated 93% good to excellent results using an endoscope, speculum, and tunneling forceps. Over the past decade, increasing interest in elbow arthroscopy and advancements in techniques have led to expanded indications for its use to treat various disorders involving the elbow.25–27 An arthroscopic technique for ulnar nerve decompression might have similar advantages to those of other joints, including simultaneous intra-articular joint evaluation, decreased postoperative scarring and soft tissue trauma, shortened need for immobilization, and less vascular disruption to the ulnar nerve.15 The trend toward in situ ulnar nerve decompression over transposition has been supported by numerous authors and has stemmed mainly from the benefits found using these less-invasive procedures.15,18,28 –32 In a prospective randomized study, Nabhan et al30 compared simple decompression with anterior subcutaneous transposition in 66 patients with cubital tunnel syndrome. Thirty-two patients had simple decompression, and 34 had anterior subcutaneous transposition. No notable difference in pain, motor and sensory deficits, or nerve conduction velocity studies were found between the 2 groups with 3 to 9 month follow-up. The authors recommended simple decompression of the ulnar nerve. Bartels et al31 performed a prospective randomized trial on 75 simple decompressions and 77 anterior subcutaneous transpositions. The authors found no difference in clinical outcome between the 2 groups. The complication rate was 10% in the simple decom-
667
pression group and 31% in the transposition group. The authors concluded that simple decompression was technically easier to perform due to reduced soft tissue dissection and the absence of need for muscle detachment. In addition, the authors noted that simple decompression was associated with fewer complications, even in the presence of postoperative ulnar nerve subluxation. Biggs and Curtis32 reported on 23 in situ decompressions and 21 submuscular transpositions. The results were equally effective, but 3 deep wound infections developed in the transposition group. The authors concluded that in situ release is equally effective, with fewer complications. Elbow arthroscopy for ulnar nerve decompression carries its own risks. Complications involving elbow arthroscopy average about 10%, which is markedly greater than for knee arthroscopy (1% to 2%).33 These risks include nerve palsy, persistent drainage from portal incision sites, and persistent joint contractures. This study also noted the diagnosis of rheumatoid arthritis, presence of an elbow contracture, and performing a capsular release as statistically significant factors associated with nerve injury. Injuries to each of the susceptible nerves around the elbow have been reported in the literature.33–37 This information is important to consider before attempting a technically demanding procedure such as arthroscopic ulnar nerve decompression. In our series, no transient or permanent nerve injuries or other complications occurred. The limitations of this study include the fact that data were retrospectively gathered. The patients’ ages ranged widely, indicating a heterogeneous group. However, we felt the need to include all patients who met inclusion criteria in the series. Also, a disproportionate number of men compared to women were included, which is likely due to the increased frequency of elbow osteoarthritis in men, as has been shown consistently in the literature.2,20 –21,27 Although there are no reports on open or arthroscopic debridement of the elbow improving ulnar nerve function without an additional procedure on the nerve, there remains the possibility that debridement of the joint in some way decreases nerve irritation. If this is true, open or arthroscopic release of the ulnar nerve might not be needed after extensive debridement. Arthroscopic decompression of the ulnar nerve at the elbow appears to be an acceptable, minimally invasive technique for treatment of ulnar entrapment neuropathy in this small series of patients with concomitant elbow arthritis. We do not recommend arthroscopic release of the ulnar nerve for isolated ulnar neuropathy. The ability to treat nerve symptoms and arthritis with an all-
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inside technique is appealing because it allows for early mobilization and return to activity. The surgeon should have considerable experience with elbow anatomy and arthroscopic techniques before attempting this procedure. Comparative studies from other centers would possibly validate the effectiveness of this technique. REFERENCES 1. Gelberman RH, Yamaguchi K, Hollstien SB, Winn SS, Heidenreich FP Jr, Bindra RR, et al. Changes in interstitial pressure and crosssectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow. An experimental study in human cadavera. J Bone Joint Surg 1998;80A:492–501. 2. Kurosawa H, Nakashita K, Nakashita H, Sasaki S. Pathogenesis and treatment of cubital tunnel syndrome caused by osteoarthritis of the elbow joint. J Shoulder Elbow Surg 1995;4:30 –34. 3. Froimson AI, Anouchi YS, Seitz WH Jr, Winsberg DD. Ulnar nerve decompression with medial epicondylectomy for neuropathy at the elbow. Clin Orthop Relat Res 1991;265:200 –206. 4. Geutjens GG, Langstaff RJ, Smith NJ, Jefferson D, Howell CJ, Barton NJ. Medial epicondylectomy or ulnar-nerve transposition for ulnar neuropathy at the elbow? J Bone Joint Surg 1996;78B: 777–779. 5. Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg 1980;62A:820 – 825. 6. Dellon AL. Review of treatment results for ulnar nerve entrapment at the elbow. J Hand Surg 1989;14A:688 –700. 7. Ruocco MJ, Walsh JJ, Jackson JP. MR imaging of ulnar nerve entrapment secondary to an anomalous wrist muscle. Skeletal Radiol 1998;27:218 –221. 8. Rayan GM. Proximal ulnar nerve compression. Cubital tunnel syndrome. Hand Clin 1992;8:325–336. 9. Amadio PC, Beckenbaugh RD. Entrapment of the ulnar nerve by the deep flexor-pronator aponeurosis. J Hand Surg 1986;11A:83– 87. 10. Osborne G. Compression neuritis of the ulnar nerve at the elbow. Hand 1970;2:10 –13. 11. King T, Morgan FP. Late results of removing the medial humeral epicondyle for traumatic ulnar neuritis. J Bone Joint Surg 1959;41B: 51–55. 12. Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg 1980;62A:820 – 825. 13. Taleisnik J, Szabo RM. Compression neuropathies of the upper extremity. In: Chapman MW, Madison M, eds. Operative orthopaedics, 2nd ed. Philadelphia, PA: JB Lippincott, 1993:1419 –1465. 14. Leffert RD. Anterior submuscular transposition of the ulnar nerves by the Learmonth technique. J Hand Surg 1982;7:147–155. 15. Tsai TM, Chen IC, Majd ME, Lim BH. Cubital tunnel release with endoscopic assistance: results of a new technique. J Hand Surg 1999;24A:21–29. 16. Bain GI, Bajhau A. Endoscopic release of the ulnar nerve at the elbow using the Agee device: a cadaveric study. Arthroscopy 2005; 21:691– 695.
17. Nakao Y, Takayama S, Toyama Y. Cubital tunnel release with lift-type endoscopic surgery. Hand Surg 2001;6:199 –203. 18. Mariani PP, Golano P, Adriani E, Llusa M, Camilleri G. A cadaveric study of endoscopic decompression of the cubital tunnel. Arthroscopy 1999;15:218 –222. 19. Hoffmann R, Siemionow M. The endoscopic management of cubital tunnel syndrome. J Hand Surg 2006;31B:23–29. 20. Wada T, Isogai S, Ishii S, Yamashita T. Debridement arthroplasty for primary osteoarthritis of the elbow. J Bone Joint Surg 2004;86A: 233–241. 21. Antuna SA, Morrey BF, Adams RA, O’Driscoll SW. Ulnohumeral arthroplasty for primary degenerative arthritis of the elbow: longterm outcome and complications. J Bone Joint Surg 2002;84A: 2168 –2173. 22. Dellon AL. Techniques for successful management of ulnar nerve entrapment at the elbow. Neurosurg Clin N Am 1991;2:57–73. 23. Kleinman WB, Bishop AT. Anterior intramuscular transposition of the ulnar nerve. J Hand Surg 1989;14A:972–979. 24. Taniguchi Y, Takami M, Takami T, Yoshida M. Simple decompression with small skin incision for cubital tunnel syndrome. J Hand Surg 2002;27B:59 –562. 25. Steinmann SP. Elbow arthroscopy: where are we now? Arthroscopy 2007;23:1231–1236. 26. Adams JE, Wolff LH III, Merten SM, Steinmann SP. Osteoarthritis of the elbow: results of arthroscopic osteophyte resection and capsulectomy. J Shoulder Elbow Surg 2008;17:126 –131. 27. Steinmann SP, King GJ, Savoie FH III. Arthroscopic treatment of the arthritic elbow. J Bone Joint Surg 2005;87A:2114 –2121. 28. Heithoff SJ. Cubital tunnel syndrome does not require transposition of the ulnar nerve. J Hand Surg 1999;24A:898 –905. 29. Nathan PA, Keniston RC, Meadows KD. Outcome study of ulnar nerve compression at the elbow treated with simple decompression and an early programme of physical therapy. J Hand Surg 1995;20B: 628 – 637. 30. Nabhan A, Ahlhelm F, Kelm J, Reith W, Schwerdtfeger K, Steudel WI. Simple decompression or subcutaneous anterior transposition of the ulnar nerve for cubital tunnel syndrome. J Hand Surg 2005;30B: 521–524. 31. Bartels RH, Verhagen WI, van der Wilt GJ, Meulstee J, van Rossum LG, Grotenhuis JA. Prospective randomized controlled study comparing simple decompression versus anterior subcutaneous transposition for idiopathic neuropathy of the ulnar nerve at the elbow: Part I. Neurosurg 2005;56:522–530. 32. Biggs M, Curtis JA. Randomized, prospective study comparing ulnar neurolysis in situ with submuscular transposition. Neurosurg 2006; 58:296 –304. 33. Kelly EW, Morrey BF, O’Driscoll SW. Complications of elbow arthroscopy. J Bone Joint Surg 2001;83A:25–34. 34. Papilion JD, Neff RS, Shall LM. Compression neuropathy of the radial nerve as a complication of elbow arthroscopy: a case report and review of the literature. Arthroscopy 1988;4:284 –286. 35. Haapaniemi T, Berggren M, Adolfsson L. Complete transection of the median and radial nerves during arthroscopic release of posttraumatic elbow contracture. Arthroscopy 1999;15:784 –787. 36. Dumonski ML, Arciero RA, Mazzocca AD. Ulnar nerve palsy after elbow arthroscopy. Arthroscopy 2006;22:577e1– e3. 37. Ruch DS, Poehling GG. Anterior interosseous nerve injury following elbow arthroscopy. Arthroscopy 1997;13:756 –758.
JHS 䉬 Vol A, April
Arthroscopic Ulnar Nerve Decompression in the Setting of Elbow Osteoarthritis Rudy Kovachevich, MD, Scott P. Steinmann, MD
Purpose To present the technique and outcomes of arthroscopic ulnar nerve decompression at the elbow in a series of patients with associated osteoarthritis. Methods A retrospective chart review identified all patients with symptomatic ulnar compression neuropathy and osteoarthritis at the elbow treated with arthroscopic decompression between March 2002 and June 2007. Information regarding preoperative symptom severity and function, associated arthritis and other disorders of the involved extremity, postoperative symptoms and function, complications, and reoperations were reviewed from the medical record. All patients were followed up for at least 12 months, and data collection included clinical evaluations and survey correspondence. Results Thirteen patients (15 elbows) were available for review. The series consisted of patients with an average age of 51 years (range, 20 –75 y). All patients had arthroscopic ulnar nerve decompression, osteophyte resection, and capsulectomy during the same procedure. An average postoperative follow-up of 47 months revealed 7 excellent, 5 good, 1 fair, and 2 poor results. Three patients had reoperations because of persistent or recurrent symptoms. These 3 patients had severe (Dellon classification) symptoms including muscular wasting on presentation. Conclusions This technique appears to be a useful procedure for treatment of cubital tunnel syndrome at the time of elbow arthroscopic debridement arthroplasty. Additional follow-up and prospective comparative studies are indicated to further evaluate this technique. (J Hand Surg 2012;37A:663–668. Copyright © 2012 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Decompression, elbow arthroscopy, elbow osteoarthritis, ulnar nerve, ulnar neuropathy.
T
HE SUPERFICIAL POSITION of the ulnar nerve at the
cubital tunnel combined with increased intraneural pressure and decreased cubital tunnel volume with elbow flexion make the nerve susceptible to
From the Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN. Received for publication November 18, 2010; accepted in revised form January 5, 2012. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Scott P. Steinmann, MD, Mayo Clinic, Department of Orthopedic Surgery, 200 First Street SW, Rochester, MN 55905; e-mail: [email protected]. 0363-5023/12/37A04-0004$36.00/0 doi:10.1016/j.jhsa.2012.01.003
compression. Gelberman et al1 demonstrated this dynamic phenomenon in a cadaver with a decreased cross-sectional area of up to 50% and an increased intraneural pressure up to 45% from full extension to 130° of flexion. When cubital tunnel syndrome is present in the setting of associated elbow arthritis, some authors have hypothesized the primary cause to be degenerative osteophytes on the medial ridge of the olecranon and trochlea anterior and lateral to the ulnar nerve.2 Mild to moderate ulnar neuropathy with or without associated elbow osteoarthritis can be successfully treated with nonsurgical management. However, patients who fail nonsurgical measures might require surgical treatment.3–9
© ASSH 䉬 Published by Elsevier, Inc. All rights reserved. 䉬 663
664
ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
Controversy exists over the optimal technique for decompression of the ulnar nerve. Standard surgical approaches include open in situ decompression,10 medial epicondylectomy,11 subcutaneous transposition,12 intramuscular transposition,13 and submuscular transposition.14 Newer techniques using endoscopic or minimally invasive procedures have been described.15–19 In patients with symptomatic elbow osteoarthritis and associated cubital tunnel syndrome having arthroscopic debridement, the ulnar nerve is typically decompressed as a separate open or percutaneous procedure.20 –21 An alternative to these procedures is arthroscopic decompression performed at the time of osteophyte resection and capsulotomy. The purpose of this study was to present the technique and evaluate the results of arthroscopic ulnar nerve decompression in a series of patients with associated osteoarthritis. METHODS Patients Patients with elbow osteoarthritis and concomitant cubital tunnel syndrome treated with arthroscopic ulnar nerve decompression between March 2002 and June 2007 were eligible for the study. Further inclusion criteria included failure of a 6-month trial of nonsurgical management consisting of activity modification, nonsteroidal anti-inflammatory medication, use of an elbow pad, and use of a night extension splint. Exclusion criteria included less than 12 months of clinical followup, preoperative diagnosis of inflammatory or posttraumatic arthritis, or previous elbow surgery. Fifteen elbows in 13 patients were included for analysis in this study, which was approved by our institutional review board. The average age of patients in the study was 51 years (range, 20 –75 y). There were 12 men (92%) and 1 woman (8%). The procedure was performed on 9 right elbows and 6 left elbows. Nine elbows were on the dominant side. Preoperative patient characteristics are documented in Table 1. All patients complaining of pain, numbness, or paresthesias in the distribution of the ulnar nerve were examined for range of motion, 2-point discrimination, grip strength, opposition pinch strength, interosseous muscle strength, and various provocative maneuvers such as Tinel nerve percussion test, direct nerve compression, and elbow flexion. We also recorded clinical presence of intrinsic muscle wasting. The diagnosis of cubital tunnel syndrome was supported by positive nerve conduction/electrodiagnostic studies in 13 of 15 patients. Studies were performed at the authors’ institution and standardized. All studies revealed chronic
focal slowing of nerve conduction in the ulnar nerve segment crossing the elbow. Mild involvement meant focal nerve conduction slowing, normal sensory amplitudes, and no fibrillations. Moderate involvement showed focal conduction slowing with decreased sensory amplitude and some evidence of denervation on needle EMG. Severe changes showed prominent axonal loss (ie, noteworthy loss of motor amplitude on nerve conduction study) with fibrillations and loss of motor units evident on EMG. Information regarding preoperative symptom severity and function were recorded. The 3-stage Dellon classification22 was used to categorize the patients by stage of cubital tunnel syndrome. Five elbows (33%) were classified as mild, 4 (27%) as moderate, and 6 (40%) as severe. The presence and severity of elbow osteoarthritis on plain radiographs were documented for all patients. Preoperative radiographs showed osteophytes involving the tip of the olecranon and the coronoid process and ossification of the olecranon fossa in all elbows. Four elbows (27%) had substantial narrowing of the ulnohumeral articulation, but none had a complete loss of the articular space. Some degree of radiocapitellar osteoarthrosis was present in 9 elbows (60%). After surgery, ulnar nerve function was assessed using the modified Bishop rating system.23 Outcome measures in this system focus on the severity of residual symptoms, symptom improvement, postoperative work status, postoperative grip strength, and postoperative static 2-point discrimination. Residual symptoms included persistence of paresthesias and weakness noted on grip and pinch strength testing. Elbow range of motion after arthroscopic osteophyte debridement was also documented. Surgical technique The patient is placed in the lateral decubitus position for standard elbow arthroscopy. A sterile arm tourniquet is placed on the upper arm and inflated before the start of the procedure. A standard posterolateral portal is established as the arthroscopic viewing portal. From this position, a view is gained across the olecranon fossa, and this can be followed down the medial gutter of the joint. A direct posterior portal is established through the triceps, and, through this portal, an arthroscopic shaver is used to debride the posterior fat pad and gain a view of the posteromedial aspect of the elbow joint. A radiofrequency probe can also be used to debride synovium. The initial goal of the procedure is to clear the posteromedial aspect of the joint to obtain excellent visualization of the posteromedial capsule and medial gutter. A retractor can also be placed through an additional prox-
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TABLE 1.
Summary of Preoperative Patient Characteristics
Gender
Age
Side
1
F
42
Right
Right
Pharmaceutical sales
Mild
Normal
22
3.5
5
2
M
37
Right
Right
Laborer/landscaping
Mild
Normal
44
4.2
3
M
44
Left
Right
Roofing/construction
Mild
Mild
33
3.9
4
M
41
Left
Right
Forklift driver
Moderate
Severe
29
5.0
5
M
73
Right
Right
Semiretired construction foreman
Severe
Severe
36
10.0
6
M
75
Left
Right
Construction
Severe
Moderate
30
6.3
12
5–135
7
M
75
Right
Right
Pipefitter
Severe
Severe
17
3.0
10
15–135
Moderate
8
M
42
Right
Right
Industrial arts teacher
Severe
Moderate
48
8.7
9
25–120
Moderate
9
M
61
Left
Right
Rancher
Severe
Severe
30
1.5
8
10–130
Mild
10
M
62
Right
Right
Rancher
Severe
Severe
43
3.5
8
5–135
Mild
11
M
52
Right
Right
Pipefitter
Moderate
Mild
45
8.2
6
25–120
Severe
12
M
47
Right
Right
FBI agent
Mild
Mild
55
12.0
5
15–130
Mild
13
M
55
Right
Right
Salesman
Moderate
Moderate
46
7.2
7
15–140
Mild
14
M
55
Left
Right
Salesman
Moderate
Mild
48
10.5
6
15–140
Mild
15
M
74
Left
Right
Engineer
Mild
Mild
32
10.0
6
5–135
Mild
EMG
Grip Strength (kg)
Opposition Pinch Strength (kg)
Range of Motion (°)
Osteoarthritis
10–140
Mild
5
5–140
Mild
5
30–115
Mild
7
5–135
Mild
⬎15
20–135
Moderate
Mild
ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
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Case
Occupation
Dellon Classification
Two-Point Discrimination* (mm)
Hand Dominance
*Two-point discrimination measurements are an average of readings from the distal ulnar ring finger, radial small finger, and ulnar small finger.
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ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
TABLE 2.
Summary of Postoperative Findings
Case
Follow-up (mo)
Modified Bishop Score
Grip Strength (kg)
Opposition Pinch Strength (kg)
Two-Point Discrimination* (mm)
Elbow Range of Motion (°)
1
28
Excellent
30
6.9
4
0–140
2
40
Good
48
10.0
4
0–140
3
68
Excellent
52
6.5
5
15–125
4
64
Poor
36
4.4
7
0–135
5
19
Good
45
12.0
9
15–135
6
48
Poor
34
7.4
9
5–135
7
56
Poor
18
3.6
8
5–135
8
14
Good
57
10.3
5
15–125
9
72
Excellent
44
4.3
5
5–130
10
64
Excellent
50
5.2
5
0–135
11
53
Fair
48
8.8
6
15–125
12
24
Excellent
65
14.4
5
5–130
13
58
Excellent
52
9.0
4
10–140
14
55
Good
50
10.5
6
10–140
15
69
Excellent
40
12.2
5
5–135
*Two-point discrimination measurements are an average of readings from the distal ulnar ring finger, radial small finger, and ulnar small finger.
imal portal to aid in visualization of the medial gutter. After adequate space is obtained and the posteromedial capsule is well visualized, a smooth biter is brought into the joint through the direct posterior portal while viewing from the posterolateral portal. The posteromedial capsule is carefully resected, with the biter close to the humerus. The ulnar nerve should be visualized just behind the posteromedial capsule. It is not recommended to use a shaver at this point of the procedure. The posteromedial capsule is removed in a proximal to distal direction starting 3 to 4 cm proximal to the medial epicondyle. Resection of the capsule is continued down to the level of the posterior aspect of the anterior band of the medial collateral ligament. The ulnar nerve is progressively visualized and dissected free from the underlying soft tissue. At this point, the ulnar nerve is checked to ensure its release from proximal to the medial epicondyle to the posterior edge of the medial collateral ligament and to ensure that the entire posteromedial capsule has been resected. As the elbow is flexed and the more superficial structures, including the Osborne ligament, that compress the nerve are encountered, the nerve should be free enough to move away laterally toward the joint. After surgery, a standard bulky posterior plaster splint is applied. The splint is removed on the second postoperative day, and the patient is encouraged to begin full range-of-motion activities.
RESULTS In this series, 13 consecutive patients (15 elbows) were followed up for an average of 47 months (range, 14 – 69 mo). Using the modified Bishop rating system, 7 (47%) patients had excellent results, and 5 (33%) had good results. Fair and poor results were found in 1 and 2 patients, respectively (Table 2). Improvement of paresthesias was noted in 13 of 15 elbows (87%), with the remaining 2 patients having no change in their symptoms. Work status examination showed that 11 (85%) patients returned to their previous level of employment within 4 weeks, with the remaining 2 patients changing occupations due to mild to moderate continued impairment directly related to their ulnar nerve symptoms. No transient or permanent neurological complications were noted. No minor complications such as superficial wound infection, hematoma, or persistent portal site drainage were present. Reoperation occurred in 3 patients, 2 of whom had subsequent open subcutaneous transpositions and one who had open in situ decompression. The 2 patients who had ulnar nerve transpositions had advanced disease (Dellon classification, severe) with intrinsic muscle wasting. Neither patient improved after this second procedure. The final patient had minor improvement with arthroscopic decompression but chose to have open in situ decompression due to continued moderate symptoms. An anconeus ep-
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ARTHROSCOPIC ULNAR NERVE DECOMPRESSION
itrochlearis muscle was found and released. The patient had mild improvement in his ulnar nerve symptoms. DISCUSSION This study reviews the treatment results of arthroscopic cubital tunnel release in patients with associated elbow osteoarthritis. We report that the vast majority (87%) of patients had improvement in paresthesias after surgery, with 80% showing excellent to good results according to the modified Bishop rating system, which is based on objective and subjective criteria as well as on work status. Numerous studies describing new, minimally invasive decompression techniques have been published in recent years and have shown positive results, although none of these studies looked specifically at patients with concomitant arthritis.15,19,24 Tsai et al15 reviewed 76 patients who they treated with a minimally invasive technique involving custom-made grooved glass tubes and a Smillie knife. They found 87% good to excellent results using the modified Bishop rating system and noted minimal complications. Hoffman and Siemionow19 demonstrated 93% good to excellent results using an endoscope, speculum, and tunneling forceps. Over the past decade, increasing interest in elbow arthroscopy and advancements in techniques have led to expanded indications for its use to treat various disorders involving the elbow.25–27 An arthroscopic technique for ulnar nerve decompression might have similar advantages to those of other joints, including simultaneous intra-articular joint evaluation, decreased postoperative scarring and soft tissue trauma, shortened need for immobilization, and less vascular disruption to the ulnar nerve.15 The trend toward in situ ulnar nerve decompression over transposition has been supported by numerous authors and has stemmed mainly from the benefits found using these less-invasive procedures.15,18,28 –32 In a prospective randomized study, Nabhan et al30 compared simple decompression with anterior subcutaneous transposition in 66 patients with cubital tunnel syndrome. Thirty-two patients had simple decompression, and 34 had anterior subcutaneous transposition. No notable difference in pain, motor and sensory deficits, or nerve conduction velocity studies were found between the 2 groups with 3 to 9 month follow-up. The authors recommended simple decompression of the ulnar nerve. Bartels et al31 performed a prospective randomized trial on 75 simple decompressions and 77 anterior subcutaneous transpositions. The authors found no difference in clinical outcome between the 2 groups. The complication rate was 10% in the simple decom-
667
pression group and 31% in the transposition group. The authors concluded that simple decompression was technically easier to perform due to reduced soft tissue dissection and the absence of need for muscle detachment. In addition, the authors noted that simple decompression was associated with fewer complications, even in the presence of postoperative ulnar nerve subluxation. Biggs and Curtis32 reported on 23 in situ decompressions and 21 submuscular transpositions. The results were equally effective, but 3 deep wound infections developed in the transposition group. The authors concluded that in situ release is equally effective, with fewer complications. Elbow arthroscopy for ulnar nerve decompression carries its own risks. Complications involving elbow arthroscopy average about 10%, which is markedly greater than for knee arthroscopy (1% to 2%).33 These risks include nerve palsy, persistent drainage from portal incision sites, and persistent joint contractures. This study also noted the diagnosis of rheumatoid arthritis, presence of an elbow contracture, and performing a capsular release as statistically significant factors associated with nerve injury. Injuries to each of the susceptible nerves around the elbow have been reported in the literature.33–37 This information is important to consider before attempting a technically demanding procedure such as arthroscopic ulnar nerve decompression. In our series, no transient or permanent nerve injuries or other complications occurred. The limitations of this study include the fact that data were retrospectively gathered. The patients’ ages ranged widely, indicating a heterogeneous group. However, we felt the need to include all patients who met inclusion criteria in the series. Also, a disproportionate number of men compared to women were included, which is likely due to the increased frequency of elbow osteoarthritis in men, as has been shown consistently in the literature.2,20 –21,27 Although there are no reports on open or arthroscopic debridement of the elbow improving ulnar nerve function without an additional procedure on the nerve, there remains the possibility that debridement of the joint in some way decreases nerve irritation. If this is true, open or arthroscopic release of the ulnar nerve might not be needed after extensive debridement. Arthroscopic decompression of the ulnar nerve at the elbow appears to be an acceptable, minimally invasive technique for treatment of ulnar entrapment neuropathy in this small series of patients with concomitant elbow arthritis. We do not recommend arthroscopic release of the ulnar nerve for isolated ulnar neuropathy. The ability to treat nerve symptoms and arthritis with an all-
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inside technique is appealing because it allows for early mobilization and return to activity. The surgeon should have considerable experience with elbow anatomy and arthroscopic techniques before attempting this procedure. Comparative studies from other centers would possibly validate the effectiveness of this technique. REFERENCES 1. Gelberman RH, Yamaguchi K, Hollstien SB, Winn SS, Heidenreich FP Jr, Bindra RR, et al. Changes in interstitial pressure and crosssectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow. An experimental study in human cadavera. J Bone Joint Surg 1998;80A:492–501. 2. Kurosawa H, Nakashita K, Nakashita H, Sasaki S. Pathogenesis and treatment of cubital tunnel syndrome caused by osteoarthritis of the elbow joint. J Shoulder Elbow Surg 1995;4:30 –34. 3. Froimson AI, Anouchi YS, Seitz WH Jr, Winsberg DD. Ulnar nerve decompression with medial epicondylectomy for neuropathy at the elbow. Clin Orthop Relat Res 1991;265:200 –206. 4. Geutjens GG, Langstaff RJ, Smith NJ, Jefferson D, Howell CJ, Barton NJ. Medial epicondylectomy or ulnar-nerve transposition for ulnar neuropathy at the elbow? J Bone Joint Surg 1996;78B: 777–779. 5. Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg 1980;62A:820 – 825. 6. Dellon AL. Review of treatment results for ulnar nerve entrapment at the elbow. J Hand Surg 1989;14A:688 –700. 7. Ruocco MJ, Walsh JJ, Jackson JP. MR imaging of ulnar nerve entrapment secondary to an anomalous wrist muscle. Skeletal Radiol 1998;27:218 –221. 8. Rayan GM. Proximal ulnar nerve compression. Cubital tunnel syndrome. Hand Clin 1992;8:325–336. 9. Amadio PC, Beckenbaugh RD. Entrapment of the ulnar nerve by the deep flexor-pronator aponeurosis. J Hand Surg 1986;11A:83– 87. 10. Osborne G. Compression neuritis of the ulnar nerve at the elbow. Hand 1970;2:10 –13. 11. King T, Morgan FP. Late results of removing the medial humeral epicondyle for traumatic ulnar neuritis. J Bone Joint Surg 1959;41B: 51–55. 12. Eaton RG, Crowe JF, Parkes JC III. Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg 1980;62A:820 – 825. 13. Taleisnik J, Szabo RM. Compression neuropathies of the upper extremity. In: Chapman MW, Madison M, eds. Operative orthopaedics, 2nd ed. Philadelphia, PA: JB Lippincott, 1993:1419 –1465. 14. Leffert RD. Anterior submuscular transposition of the ulnar nerves by the Learmonth technique. J Hand Surg 1982;7:147–155. 15. Tsai TM, Chen IC, Majd ME, Lim BH. Cubital tunnel release with endoscopic assistance: results of a new technique. J Hand Surg 1999;24A:21–29. 16. Bain GI, Bajhau A. Endoscopic release of the ulnar nerve at the elbow using the Agee device: a cadaveric study. Arthroscopy 2005; 21:691– 695.
17. Nakao Y, Takayama S, Toyama Y. Cubital tunnel release with lift-type endoscopic surgery. Hand Surg 2001;6:199 –203. 18. Mariani PP, Golano P, Adriani E, Llusa M, Camilleri G. A cadaveric study of endoscopic decompression of the cubital tunnel. Arthroscopy 1999;15:218 –222. 19. Hoffmann R, Siemionow M. The endoscopic management of cubital tunnel syndrome. J Hand Surg 2006;31B:23–29. 20. Wada T, Isogai S, Ishii S, Yamashita T. Debridement arthroplasty for primary osteoarthritis of the elbow. J Bone Joint Surg 2004;86A: 233–241. 21. Antuna SA, Morrey BF, Adams RA, O’Driscoll SW. Ulnohumeral arthroplasty for primary degenerative arthritis of the elbow: longterm outcome and complications. J Bone Joint Surg 2002;84A: 2168 –2173. 22. Dellon AL. Techniques for successful management of ulnar nerve entrapment at the elbow. Neurosurg Clin N Am 1991;2:57–73. 23. Kleinman WB, Bishop AT. Anterior intramuscular transposition of the ulnar nerve. J Hand Surg 1989;14A:972–979. 24. Taniguchi Y, Takami M, Takami T, Yoshida M. Simple decompression with small skin incision for cubital tunnel syndrome. J Hand Surg 2002;27B:59 –562. 25. Steinmann SP. Elbow arthroscopy: where are we now? Arthroscopy 2007;23:1231–1236. 26. Adams JE, Wolff LH III, Merten SM, Steinmann SP. Osteoarthritis of the elbow: results of arthroscopic osteophyte resection and capsulectomy. J Shoulder Elbow Surg 2008;17:126 –131. 27. Steinmann SP, King GJ, Savoie FH III. Arthroscopic treatment of the arthritic elbow. J Bone Joint Surg 2005;87A:2114 –2121. 28. Heithoff SJ. Cubital tunnel syndrome does not require transposition of the ulnar nerve. J Hand Surg 1999;24A:898 –905. 29. Nathan PA, Keniston RC, Meadows KD. Outcome study of ulnar nerve compression at the elbow treated with simple decompression and an early programme of physical therapy. J Hand Surg 1995;20B: 628 – 637. 30. Nabhan A, Ahlhelm F, Kelm J, Reith W, Schwerdtfeger K, Steudel WI. Simple decompression or subcutaneous anterior transposition of the ulnar nerve for cubital tunnel syndrome. J Hand Surg 2005;30B: 521–524. 31. Bartels RH, Verhagen WI, van der Wilt GJ, Meulstee J, van Rossum LG, Grotenhuis JA. Prospective randomized controlled study comparing simple decompression versus anterior subcutaneous transposition for idiopathic neuropathy of the ulnar nerve at the elbow: Part I. Neurosurg 2005;56:522–530. 32. Biggs M, Curtis JA. Randomized, prospective study comparing ulnar neurolysis in situ with submuscular transposition. Neurosurg 2006; 58:296 –304. 33. Kelly EW, Morrey BF, O’Driscoll SW. Complications of elbow arthroscopy. J Bone Joint Surg 2001;83A:25–34. 34. Papilion JD, Neff RS, Shall LM. Compression neuropathy of the radial nerve as a complication of elbow arthroscopy: a case report and review of the literature. Arthroscopy 1988;4:284 –286. 35. Haapaniemi T, Berggren M, Adolfsson L. Complete transection of the median and radial nerves during arthroscopic release of posttraumatic elbow contracture. Arthroscopy 1999;15:784 –787. 36. Dumonski ML, Arciero RA, Mazzocca AD. Ulnar nerve palsy after elbow arthroscopy. Arthroscopy 2006;22:577e1– e3. 37. Ruch DS, Poehling GG. Anterior interosseous nerve injury following elbow arthroscopy. Arthroscopy 1997;13:756 –758.
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