Comparison of surgical out come between virgin carpal tunnel syndrome and previous local steroid injected tunnel

Carpal tunnel syndrome(CTS) is the most commonly occurring peripheral nerve compression neuropathy and its condition characterized by an abnormality of the median nerve function due to compression of the nerve within the carpal tunnel. Surgical release of the transverse carpal ligament is an effective treatment for patients with CTS. Non-steroidal anti-inflammatory drugs, diuretics, vitamin B6 injection, ultrasound therapy, laser therapy, acupuncture, magnetic therapy, bracing and local steroid injections have been used for closed treatment of CTS and effective results in the short-term treatment have been demonstrated clearly only for bracing and local steroid injections. Aim: was to identify the effect of local steroid injection on the outcome of surgical release of CTS. A prospective study that was conducted in the Orthopedic Department of at Basra General Hospital during the period from 1st of July 2005 till end of September 2006 on 40 patients, 20 of them with received local steroid injection (group A) and 20 without local steroid injection (group B virgin carpal tunnel) operations done to release the tunnel with monthly follow up by telephone call because of social and security problems at time of study. Pearson’s Chi–square test was used to assess statistical association between injection of local steroid and outcome of CTS surgery. A level of P – value less than 0.05 was considered significant. Postoperatively, in Group A, night pain and grip power were found to be improved in 17 (85%) and 11 (55%) of women, respectively, while 16 (80%) relieved from night pain, paresthesia and numbness. On the other hand, the postoperative follow up of women in group B showed that the improvement of night pain was occurred in 20 cases (90%), relieving of night pain, paresthesia and numbness in 17 (85%), and improvement of grip power was reported in 12 (60%). The analysis of association didn’t show statistical significant difference (P > 0.05) in surgical outcome between study groups. In conclusion; local steroid injection for CTS prior to surgery didn’t affect outcome of surgical release.


Introduction
Carpal tunnel syndrome(CTS) is most broadly defined as a condition characterized by an abnormality of the median nerve function due to compression of the nerve within the carpal tunnel (1). It's the most commonly occurring peripheral nerve compression neuropathy (2). A recent population-based study established a prevalence of 2.7% for CTS in the general population (3). It occurs most often in patients between 30 and 60 years old and it is five times more frequent in women than in men (4). It's cause impairment of motor and /or sensory function of the median nerve as it traverses through the carpal tunnel. Its caused either by intrinsic swelling of the median nerve or by extrinsic compression of the nerve by one of many surrounding structures of wrist (5). Harrington et al suggested surveillance diagnostic criteria for CTS should include pain or paranesthesia or sensory loss in the median nerve distribution and one of (Tinel's test positive, Phalen's test positive, nocturnal exacerbation of symptoms, motor loss with wasting of the abductor pollicis brevis, or abnormal nerve conduction studies) (6). Tinel's test (percussion of the median nerve at the wrist creating tingling in the median innervated fingers) is considered to have a specificity of 99% and a sensitivity of 64% (7).
Phalen's test (wrist flexion provoking tingling in median innervated fingers within 60 seconds) has a 95% specificity with a sensitivity of 75% (8). Non-steroidal anti-inflammatory drugs, diuretics, vitamin B6 injection, ultrasound therapy, laser therapy, acupuncture, magnetic therapy, bracing and local steroid injections have been used for closed treatment of CTS and effective results in the short-term treatment have been demonstrated clearly only for bracing and local steroid injections (9). Local steroid injection for CTS was shown to provide greater clinical improvement in symptoms one month after injection compared with placebo (10).
Surgical release of the transverse carpal ligament is an effective treatment for patients with CTS. Surgical release is indicated for failed conservative treatment, severe symptoms at presentation and various disease states like diabetes, rheumatoid arthritis or CTS with cervical spondylosis when occur together and may exacerbate one another (double crush). Open surgery is easy and cheap and can be done by the general surgeon with a good anatomical knowledge of the hand (11). Failure to benefit from decompression may arise from concomitant disease (for example diabetes) or as a double crush phenomenon with additional nerve root irritation at cervical spine level. Patients who have experienced severe prolonged compression may have intra-neural fibrosis with a more limited recovery postoperatively (12).
Aim of this study was to identify the effect of local steroid injection on the outcome of surgical release of CTS.

Patients and methods
Study design, setting: This was a prospective study that was conducted in the Orthopedic

Statistical analysis
The data analyzed using Statistical Package for Social Sciences (SPSS) version 25. The data presented as mean, standard deviation and ranges. Categorical data presented by frequencies and percentages. Pearson's Chi-square test was used to assess statistical association between injection of local steroid and outcome of CTS surgery. A level of Pvalue less than 0.05 was considered significant.

Results
A total of 40 women with CTS were the subjects of this study. Mean age was 35.37 ± 10.06 years ranging from 20 to 60 years. Most of women 28 (70%) were in the age group of 20-40 years, and 37 (92.5%) were married. CTS was right-sided in 19 (47.5%) cases, left-sided in 5       [4]. They were near to result in Gonzalez et al study, as numbness found in 93% of cases [5]. Differences observed are due to sample size, age and gender of patients, occupation and comorbid diseases, concerning the difference in provocation tests, they might due to nonhomogenous characters of examined patients. Different degree in progression of the condition, as well as methods of performing these tests, as seem to play a significant role specially the percussion Tinel΄s test [6]. In the present study, the postoperative follow up of patients treated surgically, improvement and relieving of night pain, paresthesia and numbness was better than those treated by steroid, despite non-significant association (P>0.05). In accordance to Ly-Pen study in 2012, who found at the 24-month follow-up, surgery nonsignificantly was more effective than injection in those achieving 70% improvement (P = 0.049) [7]. Similarly, Ren et al study found that functional improvement, symptom improvement and neurophysiological improvement at different follow-up times showed that the differences were non-significant between surgical and non-surgical interventions [8][9][10].
Differently, Klokkari and colleagues found that surgical treatment had a greater and significant improvement of symptoms and neurophysiological parameters at six months. While, at 3 and 12 months, the results were not significant in favor of surgery or conservative treatment (P>0.05) [11][12][13]. Differently also, at 20 weeks after randomization in Hui et al study, surgery had a significant greater symptomatic improvement than those with steroid injection (p<0.001) [14]. Differences observed can attributed to sample size of each study, duration and severity of the symptoms, follow-up duration, numbers of steroid trails, attendance of patients for follow-up and type of CTS (primary or secondary).
It seemed that the local steroid injection could lead to a transient improvement in electrophysiological parameters one month after injection by the anti-inflammatory and antiedema effects of the corticosteroid or by inhibiting the spontaneous discharge ability of excitable cells [15]. On the other hand, surgical decompression has traditionally been considered the definitive treatment for CTS. Surgical treatment appears to be more effective for the symptoms of CTS than other non-surgical procedure [16].

Ethical Approval
The study was approved by the Ethical Committee.

Conflicts of Interest
The author declare that he has no competing interests.