Acta Neurochir DOI 10.1007/s00701-013-1962-z
CLINICAL ARTICLE - NEUROSURGICAL TECHNIQUES
Comparative outcomes of ulnar nerve transposition versus neurolysis in patients with entrapment neuropathy at the cubital tunnel: a 20-year analysis A. S. Kamat & S. M. Jay & L. A. Benoiton & J. A. Correia & K. Woon
Received: 11 October 2013 / Accepted: 22 November 2013 # Springer-Verlag Wien 2013
Abstract Background Entrapment neuropathy of the ulnar nerve at the level of the elbow is the shared domain of multiple surgical specialties. A wide variety of operative methods for its surgical management have been reported. Our hospital utilizes neurolysis (NL) and subcutaneous transposition (AST). The aim of this paper was to compare the clinical outcomes in patients treated by ulnar nerve transposition versus neurolysis over a 20-year period. Methods We included patients who underwent either neurolysis or an ulnar nerve transposition. A retrospective analysis was performed which included 480 patients at our institution between January 1992 and December 2012. In total, physical and electronic records for 480 patients were reviewed. Three-hundred and one underwent ulnar nerve transposition and 179 underwent ulnar nerve neurolysis . Results In the AST group 201/301 patients suffered from parasthesiae pre-operatively and 156/301 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 99/301 patients. At the 3-month follow-up appointment, 187/201 patients with parasthesiae and 113/156 patients with local pain had resolution of their symptoms. In the NL group 151/179 patients had parasthesiae pre-operatively and 126/179 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 56/179 patients. At the 3-month follow-up
Presented at the 15th Congress of the World Federation of Neurological Societies, 11th September 2013, Seoul, South Korea. A. S. Kamat (*) : S. M. Jay : L. A. Benoiton : J. A. Correia : K. Woon Department of Neurosurgery, Wellington Regional Hospital, Riddiford StWellington South Wellington, New Zealand e-mail:
[email protected]
appointment, 141/151 patients with parasthesiae and 117/ 126 patients with local pain had resolution of their symptoms. Conclusions In cases of ulnar nerve compression at the cubital tunnel, both neurolysis and transposition are effective in improving clinical outcome. The only statistically significant advantage of neurolysis over transposition seems to be relief of localized elbow pain. We recommend neurolysis as the preferred procedure. Keywords Neurolysis . Transposition . Decompression . Ulnar nerve
Introduction Entrapment neuropathy of the ulnar nerve at the level of the elbow is the shared domain of multiple surgical specialties and, due to the overlay between these surgical specialities, a wide variety of operative methods for its surgical management have been reported. It is the second most frequent nerve compression syndrome in the arm [1]. The management of ulnar entrapment neuropathy at the elbow initially comprises non-operative measures which include rest, splinting, and physiotherapy [2, 3]. Operative intervention is indicated in patients with evidence of progressive symptomatology and those who do not respond to a period conservative treatment. There are currently five different methods employed for operative management. They include simple decompression of the ulnar nerve (neurolysis) [1, 4], medial epicondylectomy [4], and subcutaneous, submuscular or intramuscular [2, 5] anterior transposition of the ulnar nerve. Whether surgical mobilization of the ulnar nerve during anterior transposition has an adverse effect on the blood supply to the nerve and hence its overall function is controversial. Other controversies include whether simple decompression is not adequate enough to relieve symptoms [5, 6]. Surgeons who
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advocate for nerve transposition are concerned with addressing the issue of dynamic compression of the ulnar nerve that occurs with elbow flexion. Those who prefer neurolysis believe that it produces fewer complications than transposition and does not compromise the blood supply of the nerve [7]. Anterior subcutaneous transposition of the ulnar nerve is the oldest procedure and the most commonly utilized [8, 9]. However, neurolysis is technically a much simpler procedure, and equivalent if not better results are claimed [10, 11]. Our hospital utilizes neurolysis and subcutaneous transposition only. Our neurosurgical department favours neurolysis, and our orthopaedic hand surgeon colleagues favour anterior transposition of the ulnar nerve. Both procedures have been associated with favourable outcomes [4, 6, 12]. The aim of this paper was to compare the clinical outcomes in patients treated by anterior subcutaneous transposition versus simple decompression (neurolysis) over a 20-year period at a single centre.
Table 1 Patient demographic Patient demographic
Anterior transposition
Neurolysis
Patients Age range (years) Mean age (years) Sex (M:F) Mean symptom duration (months)
301 29 to 86 49 101:200 15
179 30 to 79 51 84:95 15
pain, power and sensation in their hands with special mention of changes in symptoms. Patients were reviewed for 3 months post-operatively. The main outcome measured was symptoms as per the McGowan classification (Table 2). Patients were also asked through a questionnaire about their level of satisfaction. Options provided included satisfied, dissatisfied or neither.
Surgical technique Materials and methods Anterior subcutaneous transposition (AST) A retrospective analysis was performed which included 480 patients at our institution between January 1992 and December 2012. Our study included patients who underwent either a simple ulnar nerve neurolysis or transposition. Inclusion criteria were patients with evidence of an ulnar entrapment neuropathy at the cubital tunnel that had been confirmed on nerve conduction studies. All patients were initially trialled with nonoperative treatment initially. The length of time of this was at the discretion of the surgeon. Those patients that did not meet these criteria were excluded from the study. Other exclusion criteria were patients who had a previous fracture involving the elbow and patients with a superimposed foraminal stenosis of the cervical spine that resulted in radicular symptoms. Patients lost to follow-up were also excluded from the study. Both clinical records and nerve conduction studies for a total of 480 patients were reviewed. Three-hundred and one underwent ulnar nerve transposition by the orthopaedic hand surgeons at our institution. The remaining 179 underwent ulnar nerve neurolysis by the neurosurgeons at our hospital. In the transposition group, 200 patients were women and 101 were men with an age range of 29 to 86 years (mean age of 49). In the neurolysis group, 95 patients were women and 84 were men with an age range of 30 to 79 years (mean age of 51). The average duration of symptoms for all patients was 15 months with a range of 6–23 months (Table 1). Patients were consulted about their symptoms prior to surgery and classified as per the McGowan classification system [1]. In the transposition group, 191 patients were classified as grade 1, 80 as grade 2 and 30 as grade 3. In the neurolysis group, 92 patients were classified as grade 1, 56 as grade 2, 31 as grade 3. Post-operatively, patients were asked to report changes to
All anterior subcutaneous transpositions were performed under general anaesthesia and with the use of tourniquet control. Through a 10-cm medial incision centred on the medial epicondyle, the ulnar nerve was identified proximal to the medial epicondyle. Dissection was then continued down to Osborne’s fascia which was divided. The fascia between the two heads of flexor carpi ulnaris was then divided. The ulnar nerve was then mobilised. The common flexor origin was incised and allowed to migrate distally. This created a groove on the anterior aspect of the medial epicondyle. The ulnar nerve was subsequently transposed and held in position with a single suture into the subcutaneous tissue and down onto the medial epicondyle. To ensure that there was no residual compression of the transposed nerve, the elbow was flexed and extended. Underlying tissues were closed in layers and dissolvable sutures used for the skin. Neurolysis (NL) All neurolyses were performed under general anaesthesia without the use of tourniquet control. A 5-cm curvilinear Table 2 McGowan classification system 0 1 2 3
No symptoms Minimal lesions, parasthesia and dysthesia, no wasting or weakness of ulnar intrinsic muscles Intermediate lesions, weakness and wasting of interossei but some voluntary power is retained Severe lesions, paralysis of interossei and marked weakness of the hand
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incision was made on the medial aspect of the elbow with the curve extending anteriorly and lateral to the medial epicondyle. The incision was taken to superficial to the muscular fascial layer and then undermined to expose the olecranon groove. Proximal to this, the ulnar nerve was identified and mobilized. Then the fascial layer over the olecranon groove was divided to expose the compressed ulnar nerve. This was decompressed and the nerve followed into the cubital tunnel between the two heads of flexor carpi ulnaris with subsequent division of the fascia of this muscle to decompress the nerve. The nerve was then mobilised and confirmed not to be compressed or kinked when the elbow was flexed and extended. Underlying tissues were closed in layers and dissolvable sutures are used for the skin. The use of general anaesthetic instead of local anaesthetic was due to surgeon preference at our institution.
Results Anterior subcutaneous transposition In this group 201/301 patients had parasthesiae preoperatively and 156/301 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 99/301 patients (Table 3). At the 3-month follow-up appointment, 187/201 (93 %) patients with parasthesiae and 113/156 (72.4 %) patients with local pain had resolution of their symptoms. Fourteen patients had no change in their parasthesiae despite having improved nerve velocities of the ulnar nerve and 55 patients had ongoing local pain. Ten of these 55, however, did state that their pain had improved despite still being present. Paresis completely resolved in 78 patients. Eleven patients had increased power at the 3-month follow-up and the remainder reported no change (Table 4). There were 18 complications in total. Seven patients had superficial wound infections that resolved with a course of oral antibiotics, two had deep infections requiring washout and wound debridement, and nine had complex regional pain syndrome. With regards to patient satisfaction, 94 % were satisfied with their respective outcomes after anterior subcutaneous transposition. Duration and severity of symptoms did not influence outcome. Mean operative time was 72 min. Table 3 Pre-operative signs and symptoms (number of patients)
Pain Parasthesia Weakness Atrophy
Anterior transposition
Neurolysis
156 201 99 25
126 151 56 15
Neurolysis (simple decompression) In this group 151/179 patients had parasthesiae preoperatively and 126/179 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 56/179 patients (Table 3). At the 3-month followup appointment, 141/151 (93.3 %) patients with parasthesiae and 117/126 (92.8 %) patients with local pain had resolution of their symptoms. Eleven patients had no change in their parasthesiae despite having improved nerve velocities of the ulnar nerve and 12 patients had ongoing local pain. Ten of these 12 patients, however, did state that their pain had improved despite still being present. Paresis completely resolved in 48 patients. Five patients had increased power at the 3month follow-up and the remainder reported no change (Table 4). There were six complications in total. Four patients had superficial wound infections that resolved with a course of oral antibiotics, and two had complex regional pain syndrome. With regards to patient satisfaction, 97 % were satisfied with their respective outcomes after neurolysis. Duration and severity of symptoms did not influence outcome. Mean operative time was 52 min. When classifying patients according to the McGowan system, 99 % of patients with grade 1, 88 % of patients with grade 2 and 72 % of patients with grade 3 showed symptom resolution. Pre- and Post-operative findings when stratified as per the McGowan system are documented in Table 4.
Discussion Numerous surgical techniques have been suggested and advocated for the treatment of entrapment neuropathy of the ulnar nerve at the cubital tunnel. In 1957, Osborne proposed that ulnar nerve palsy was caused by compression [13]. He reported the existence of a band of fibrous tissue bridging the head of the flexor carpi ulnaris. This band lies directly over the ulnar nerve. He noticed that it was slack during elbow extension but tight with flexion of the elbow. The division of this band (Osborne’s fascia) was deemed enough to relieve the symptoms. Feindel and Stratford in 1958 proposed the same theory of compression of the ulnar nerve in the cubital tunnel [10]. Anterior transposition and neurolysis are the commonest procedures performed both globally and at our hospital [3, 11, 14, 15]. Many authors report worsening of symptoms after anterior transposition [16–18]. This may be attributed to devascularisation of the nerve by obliteration of the epineural vessels [19–21]. This, however, was not experienced at our institution. In neurolysis, the ulnar nerve is left in its original position without risk of segmental ischemia due to ligation of segmental blood vessels [22]. Several authors have stipulated
Acta Neurochir Table 4 Number of patients with residual signs and symptoms after surgery using the McGowan classification McGowan grade 1 McGowan grade 2 McGowan grade 3
Transposition group (n =301)
Neurolysis group (n =179)
Pre-operative symptoms
Post-operative residual symptoms
Pre-operative symptoms
Post-operative residual symptoms
201 90 10
14 17 4
151 50 6
10 6 2
that simple decompression may be as beneficial to patient’s symptoms as anterior transposition and may have fewer complications [7, 10, 13, 17]. Our study design is solely focused on clinical outcome and hence demonstrates that both procedures described make a positive difference to patient symptoms. With regards to pain at the medial epicondyle, both procedures resulted in an improvement in patient symptoms. In patients who underwent AST, 35.2 % of patients had residual localized pain at 3 months compared to 9.5 % of patients in the NL group. The data analysis suggests that NL was superior to AST in reducing localised elbow pain. This was statistically significant (p
