A multicentre, randomized controlled trial of neurolysis for mild ulnar neuropathy at the elbow

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment
neuropathy and is frequently encountered in general practice. There is no
international consensus for the treatment of ulnar neuropathy at the elbow
(UNE). The management of UNE varies from non-operative measures to surgery.
Especially in mild cases with purely sensory signs, a trial of conservative
treatment is usually advocated. It is not clear at what stage patients with UNE
should be operated. Patients with moderate to severe muscle weakness of the by
the ulnar nerve innervated muscles and the patients who develop progressive
muscle weakness are usually referred for surgery. This contrasts with common
practice in patients with CTS who are often operated, even when neurological
examination is normal and nerve conduction studies show only minor
abnormalities. We demonstrated that patients with purely sensory signs of UNE
do not necessarily represent the less severe (or benign) side of the spectrum
of UNE, because 45% of the patients with purely sensory signs had
electromyographic abnormalities indicating injury of motor axons. At present
there are no randomized studies that compared surgery with conservative
treatment measures in patients with mild UNE. Most studies on the effect of
surgery in UNE compare different surgical techniques (3). In a non-randomized
study with a relative small number of patients with mild to severe UNE we found
an advantage of surgery over conservative treatment; 35% of the conservative
group showing a good outcome versus 61% in the operated group. Bartels et al
reported a good outcome after surgery in 48% of the patients. Therefore a
clinical randomized trial is warranted to evaluate the effect of surgery in
patients with mild UNE.

Primary objective:
The primary objective of this study is to compare the short-term and long-term
efficacy of neurolysis and a conservative strategy for relieving symptoms in
mild cases of UNE.

Secondary objectives:
- VAS score for paresthesias
- VAS score for pain at the hand
- VAS score for numbness
- Frequency of adverse events ascribed to the therapy (e.g. surgery
complications in the operated group)
- Number of patients that drop out because they needed surgery
- Socio-economic parameters: work situation; sick leave, change in work /
adapted function at work
- Functional scales: SF-36 and McGill Pain questionnaire

A randomized controlled multi-center trial with two arms: neurolysis and
conservative treatment.

4.1 Surgical treatment
Surgical treatment of ulnar neuropathy will be simple decompression. In this
procedure a 6 to 8 cm curvilinear incision is made, overlying the course of the
ulnar nerve as it traverses the elbow lateral to the medial epicondyle. The
deep fascia overlying the nerve is divided and the nerve is followed distally
into the postcondylar groove. The roof of the cubital tunnel is formed by the
cubital tunnel retinaculum or arcuate ligament. This fascial roof between the
medial epicondyle and olecranon is divided in a proximal to distal direction
(5) If (sub)luxation of the ulnar nerve is observed during surgery an anterior
transposition procedure may be performed by the operating neurosurgeon. The
presence of (sub)luxation will be established by flexing the elbow after
division of the arcuate ligament. Luxation is present when the ulnar nerve
moves anteriorly out of the sulcus into the space in front of the medial
epicondyle. Subluxation is present when there is anterior displacement of the
ulnar nerve out of its bed, but the nerve remains posterior to the medial
epicondyle (3). The findings during surgery will be recorded and if there are
signs of compression, the level of compression will be measured from the center
of the medial epicondyle. After surgery patients are encouraged to use their
arm as soon as possible.

5.2 Conservative treatment
Conservative treatment consists of written instructions involving posture of
the afflicted elbow. A splint will not be prescribed. The instructions are the
following. Try to minimize elbow flexion and keeping the elbow extended as much
as possible. Avoid repetitive elbow flexion and extension or direct pressure on
the elbow. Patients are advised to avoid crossing their arms when sitting, and
to rest the arm supinated on the thigh. The telephone should be held in the
other hand, with excessive reading a book stand is advised. At work a pillow
should be placed beneath the elbow on the desk, and keyboard height and angle
should be adjusted. Patients are allowed to take analgetic medication.

Patients will have to visit the outpatient clinic 4 times (baseline visit and
three follow-up visits), which is one to two times more than is usual for
patients with this diagnosis. At these visits three questionnaires have to be
filled in, and patients will undergo a short physical examination, which is
standard procedure. They will undergo electrophysiological examinations once,
these are standard diagnostic tests for every patient with UNE. The surgical
procedure that will be performed in half of the patients is a standard
operating procedure for treating UNE.