|Year : 2019 | Volume
| Issue : 3 | Page : 71-75
Long-term surgical outcome of median nerve injuries
Mohammadreza Emamhadi1, Hamid Behzadnia2, Sasan Andalib3
1 Brachial Plexus and Peripheral Nerve Injury Center, Guilan University of Medical Sciences, Rasht, Iran
2 Department of Neurosurgery, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
3 Neuroscience Research Center, Department of Neurosurgery, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences; Road Trauma Research Center, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran; Department of Nuclear Medicine, Odense University Hospital; Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark, Iran
|Date of Submission||19-Mar-2018|
|Date of Decision||05-Nov-2018|
|Date of Acceptance||21-Dec-2018|
|Date of Web Publication||17-Jun-2019|
Dr. Hamid Behzadnia
Department of Neurosurgery, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht
Dr. Sasan Andalib
Neuroscience Research Center, Department of Neurosurgery, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht
Source of Support: None, Conflict of Interest: None
Background: Median nerve integrity is a prerequisite of normal hand function. The median nerve is a frequently injured nerve, and recent evidence indicates that nerve surgery may produce acceptable outcomes. The present study provides a framework of long-term surgical outcomes of median nerve injuries and specifies independent predictors of motor and sensory recovery.
Materials and Methods: In the retrospective study, patients with median nerve injuries undergoing the nerve surgery were reviewed. Mechanism of injury, level of injury (arm, elbow/forearm, and wrist), type of injury and lesion, type of surgical repair, and the time interval from injury to surgery were assessed. The long-term follow-up of motor recovery, sensory recovery, and quality of life was done.
Results: A total of 106 cases with median nerve injuries undergoing nerve surgery were included in this study. Most injuries were at wrist level with a higher frequency of sharp and not in continuity lesions. There was a significant association between the three outcomes (motor recovery, sensory recovery, and quality of life) and smoking, addiction, type of injury, type of lesion, and type of nerve repair. There was a significant correlation between quality of life and muscle force recovery and between quality of life and sensory recovery. Muscle force recovery was significantly correlated with sensory recovery.
Conclusions: The findings of the present study suggest that male and young subjects, lesions in continuity, and injuries treated without grafting may show better surgical outcomes.
Keywords: Median nerve, motor recovery, nerve surgery, outcome, quality of life, sensory recovery
|How to cite this article:|
Emamhadi M, Behzadnia H, Andalib S. Long-term surgical outcome of median nerve injuries. Formos J Surg 2019;52:71-5
| Introduction|| |
A good hand function is essential for normal daily life. It is even more important than walking, bowel and bladder control, and sexual function in patients with tetraplegia. A majority of peripheral nerve injuries have been demonstrated to occur on upper extremities., Such injuries may lead to irreversible disabilities and in turn, impair the function of upper extremities and quality of life. Median nerve, whose integrity is essential for a normal hand function, is frequently injured. Some of the branches of median nerve can be used for nerve transfer., In the forearm, the flexor pronator muscles are innervated by the median nerve  except flexor carpi ulnaris. The median nerve is variable in that musculocutaneous nerve may give a communicating branch to it, or it takes one branch from posterior cord of brachial plexus. Such muscles pronate the forearm, flex the wrist and the hand digits. Median nerve injury symptomatically results in palsy in the supplied muscles, numbness of the thumb, second and third fingers, and radial side of the ring finger.,, Thus, disability in pinching and grasping may be its consequences. Surgical exploration and repair of the median nerve may be required in cases with clinical or electrophysiological evidence of median nerve injuries.,
Surgical outcomes are presumed to depend upon several environmental and biological factors such as regeneration of axons, misdirection of axons, neuronal survival, injury and nerve type, injury mechanism and location, time and method of repair, surgical technique, length of the defect, and age. It is fundamental to assess the likelihood of recovery of the nerve with patients' demographic and intervention elements to provide realistic expectations and suitable recovery. Surgical outcomes to be assessed include re-innervations, integrated sensory and motor function, pain, and patient-reported outcomes.,,
To date, there has been no surgical technique warranting recovery of the hand function following median nerve injuries  and further work seems essential to improve functional outcomes before and after peripheral nerve repair. In the present study, the aim was to assess long-term surgical outcomes of median nerve injuries and specify independent predictors of motor and sensory recovery.
| Materials and Methods|| |
In this retrospective study, traumatic median nerve patients during a 10-year period (from 2001 to 2011) of experience of a single surgeon were reviewed. The inclusion criteria were median nerve surgery due to traumatic nerve injuries between the shoulder and wrist crease. Cases with co-injuries in other peripheral nerves of the upper extremity, amputations of hand and fingers, known neuromuscular disorders or psychological disease, carpal tunnel syndrome, and those under the age of 12 years were excluded from the study. Ultimately, 106 cases (71 males and 35 females) with a mean age of 32.95 ± 14.45 were included.
In cases of transected nerves, the end-to-end epineural repair was carried out. If median nerve injury involved a lesion in continuity with negative intraoperative nerve action potentials, resection and repair with or without graft of the injured nerve would be done. In-continuity lesions with positive nerve action potentials during intraoperative testing underwent external neurolysis with or without internal neurolysis. The repair was performed using microscope with 6-0 or 7-0 nonabsorbable stitches.
Demographic [Table 1] and clinical data regarding gender, age, smoking, addiction, the mechanism of injury [Figure 1], level of injury (arm, forearm and elbow, and wrist), type of injury (sharp or crush), type of lesion (in continuity or not in continuity), type of surgical repair (external or internal neurolysis, primary or secondary suture repair, and graft repair), and the time interval between injury and surgery were collected. The follow-up was categorized into three periods of shorter than 2 years, 2–5 years, and longer than 5 years.
|Table 1: Demographic features of the subjects with median nerve injuries|
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|Figure 1: Different mechanism of median nerve injury (a) suicide attempt (b) dog bite|
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Motor recovery was assessed using Medical Research Council grading [Table 2] (the palmar abduction of digit 1 with grading “0” for no contraction to “5” for normal power). Semmes-Weinstein monofilament test  were applied to assess sensory recovery, that is, perception of cutaneous pressure threshold, reflecting re-innervations of peripheral targets [Table 3].
|Table 2: Muscle force of patients according to medical research council grading|
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|Table 3: Innervation of the cases according to Semmes-Weinstein monofilament test|
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Short form-36 (SF-36) was used to evaluate the patients' health and quality of life. It is composed of 8 different scaled scores ranging 0–100.
The present study was approved by Institutional Ethics Committee. Data management and analysis was done using SPSS software (version 21, SPSS Inc., Chicago, IL, USA). Percentage and frequency were reported for the qualitative data and mean ± standard deviation were reported for the quantitative data. Association and correlation of demographic and clinical data with motor and sensory recoveries and quality of life were assessed. P < 0.05 was considered statistically significant. Written informed consent was obtained from the participants. The present study was approved by a Local Ethics Committee.
| Results|| |
Of the 106 cases investigated in the present study, 35 cases were female (33%) and 71 cases were male (67%). The mean±standard deviation age of the subjects was 32.95 ± 14.45 years. The mean±standard deviation time interval from injury to surgery was 10.5 ± 6.5 weeks (1 day–29 weeks). Most of the injuries were found at wrist level (48.1%) with a higher frequency of sharp (56.6%) and not in continuity (56.6%) injuries.
Active movement against gravity was achieved in 35.8% of the cases [Table 2]. Older age (P = 0.056), smoking (P = 0.013), addiction (P = 0.019), sharp injury (P = 0.003), lesion not in continuity (P = 0.0001), and longer time interval between injury and surgery (P = 0.044) significantly hampered muscle force recovery. Type of surgical repair also significantly influenced muscle force recovery (P = 0.0001).
Most of the patients showed a diminished normal superficial sensation (24.5%) and protective sensation lost and intact deep pressure sensation (24.5%) [Table 3]. Smoking (P = 0.011), addiction (P = 0.038), and lesion not in continuity (P = 0.0001) significantly hampered sensory recovery [Table 3]. The type of surgical repair significantly affected sensory recovery (P = 0.001).
The mean score of SF-36 showing quality of life among all cases reached 66.51 ± 17.30 (30.00–100.00). Smoking (P = 0.0001), addiction (P = 0.0001), co-injury at the same upper extremity (P = 0.016), injury not in continuity (P = 0.017), and sharp lesion (P = 0.031) lowered quality of life of the patients. The type of surgical repair (P = 0.045) also significantly affected quality of life of the patients. Using multivariate logistic regression analysis, addiction, and the type of lesion were found to be predictors of quality of life. This indicates that nonaddicted cases achieved a better quality of life (P = 0.005; odds ratio [OR] = 21.4, 95% confidence interval [CI] = 2.6–177.6) and the nerve lesions in continuity provided higher levels of satisfaction for patients (P = 0.024; OR = 2.7, 95% CI = 1.14–6.4).
Using Spearman coefficient, a significant positive correlation was seen between quality of life and muscle force recovery (P < 0.0001, Spearman r = 0.486) and between quality of life and sensory recovery (P = 0.0001, Spearman r = 0.548). Motor recovery was significantly correlated to sensory recovery (P < 0.0001, Spearman r = 0.802).
| Discussion|| |
Despite improvements in surgical techniques, recovery after repair of peripheral nerve injuries is often disappointing and unpredictable, and independent predictors of a good prognosis are contentious. Thus, we set out the present study to assess surgical outcomes of the median nerve and its association with patients' demographic features. In the present study, a higher frequency of median nerve injuries among men was observed. It was also shown that smoking, addiction, type of lesion, and type of surgical repair were strong predictors for functional outcome of the median nerve surgery. Jaquet et al. assessed motor recovery, sensory recovery, and type of injury and found a significant association between the appearance of sensory and motor recoveries (P = 0.01, 95% CI = 0.01–0.04). No association was also found between return to work and injury type (P = 0.47). Work type (OR = 3.1; P = 0.002), injury level (OR = 2.6; P = 0.01), hand therapy (OR = 0.24; P = 0.001), and number of complications (P < 0.001) exerted an impact on return to work.
Hundepool et al. showed that age, gender, and co-injuries are strong predictors of better surgical outcomes. The duration of recovery was shorter among male and young subjects in the present study. Roganovic  showed that 68.7%, 33.3%, and 10% of distal, intermediate, and proximal median nerve repairs achieved a successful outcome. In addition, level of repair, time interval from injury to surgery, and length of nerve defect were significantly associated with clinical outcome. Yet, only repair level and time interval from injury to surgery were reported to be an independent predictor of successful outcome. In line with findings of Allan  we found no significant association between muscle force recovery and age or gender. The type of lesion was also a strong predictor of higher scores. We found no significant association between the surgical outcomes and the follow-up duration. al-Ghazal et al. showed that healing after nerve surgery was adversely affected by smoking. Similarly, we reached the same conclusion that smoking exerts negative impacts on surgical outcomes of the median nerve. The effect of tobacco smoke on nerve healing was reported. Ruijs et al. suggested that age, site, injured nerve, and delay affected prognosis following median and ulnar nerve injury repair significantly. The authors performed a meta-analysis and reported that there was an association between motor and sensory recoveries (Spearman r = 0.62, P < 0.001). Site (OR = 0.46; 95% CI = 0.20–1.10), age (OR = 4.3; 95% CI = 1.6–11.2), and delay (OR = 0.94; 95% CI = 0.90–0.98) were shown to predict motor recovery. The chance of motor recovery of the ulnar nerve was 71% lower than that of the median nerve (95% CI = 0.15–0.55; OR = 0.29). Delay (OR = 0.92; 95% CI = 0.87–0.98) and age (OR = 27.0; 95% CI = 9.4–77.6) were seen to predict sensory recovery. We found that the time interval between injury and surgery is an important predictor of motor recovery after median nerve surgery. In fact, longer time interval between injury to surgery brings a smaller chance of a favorable outcome.
| Conclusions|| |
The evidence from the present study indicates that male and young subjects, lesions in continuity and injuries treated with simple interventions bring about better surgical outcomes and smoking or addiction are associated with a poor prognosis for median nerve recovery.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Emamhadi M, Andalib S. Double nerve transfer for restoration of hand grasp and release in C7 tetraplegia following complete cervical spinal cord injury. Acta Neurochir (Wien) 2018;160:2219-24.
Martins RS, Bastos D, Siqueira MG, Heise CO, Teixeira MJ. Traumatic injuries of peripheral nerves: A review with emphasis on surgical indication. Arq Neuropsiquiatr 2013;71:811-4.
Emamhadi M, Alijani B, Ghadarjani S. Surgical outcome of ulnar nerve lesions: Not always disappointing. J Neurol Stroke 2015;3:115.
Emamhadi M, Andalib S. The first experience of triple nerve transfer in proximal radial nerve palsy. World Neurosurg 2018;109:351-5.
Emamhadi M, Alijani B, Andalib S. Long-term clinical outcomes of spinal accessory nerve transfer to the suprascapular nerve in patients with brachial plexus palsy. Acta Neurochir (Wien) 2016;158:1801-6.
Emamhadi MR, Emamhadi AR, Andalib S. Intramuscular compared with subcutaneous transposition for surgery in cubital tunnel syndrome. Ann R Coll Surg Engl 2017;99:653-7.
Emamhadi M, Chabok SY, Samini F, Alijani B, Behzadnia H, Firozabadi FA, et al.
Anatomical variations of brachial plexus in adult cadavers; A descriptive study. Arch Bone Jt Surg 2016;4:253-8.
Taylor CA, Braza D, Rice JB, Dillingham T. The incidence of peripheral nerve injury in extremity trauma. Am J Phys Med Rehabil 2008;87:381-5.
Scholz T, Krichevsky A, Sumarto A, Jaffurs D, Wirth GA, Paydar K, et al.
Peripheral nerve injuries: An international survey of current treatments and future perspectives. J Reconstr Microsurg 2009;25:339-44.
Dahlin LB. Techniques of peripheral nerve repair. Scand J Surg 2008;97:310-6.
Kim DH, Kam AC, Chandika P, Tiel RL, Kline DG. Surgical management and outcomes in patients with median nerve lesions. J Neurosurg 2001;95:584-94.
He B, Zhu Z, Zhu Q, Zhou X, Zheng C, Li P, et al.
Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries. Neural Regen Res 2014;9:661-72.
] [Full text]
Wong KH, Coert JH, Robinson PH, Meek MF. Comparison of assessment tools to score recovery of function after repair of traumatic lesions of the median nerve. Scand J Plast Reconstr Surg Hand Surg 2006;40:219-24.
Jerosch-Herold C. Should sensory function after median nerve injury and repair be quantified using two-point discrimination as the critical measure? Scand J Plast Reconstr Surg Hand Surg 2000;34:339-43.
Wang Y, Sunitha M, Chung KC. How to measure outcomes of peripheral nerve surgery. Hand Clin 2013;29:349-61.
Khambati FA, Shetty VP, Ghate SD, Capadia GD. Sensitivity and specificity of nerve palpation, monofilament testing and voluntary muscle testing in detecting peripheral nerve abnormality, using nerve conduction studies as gold standard; a study in 357 patients. Lepr Rev 2009;80:34-50.
Ahmed-Labib M, Golan JD, Jacques L. Functional outcome of brachial plexus reconstruction after trauma. Neurosurgery 2007;61:1016-22.
Ozdemir HM, Biber E, Oǧün T. The results of nerve repair in combined nerve-tendon injuries of the forearm. Ulus Travma Acil Cerrahi Derg 2004;10:51-6.
Hundepool CA, Ultee J, Nijhuis TH, Houpt P; Research Group 'ZERO', Hovius SE. Prognostic factors for outcome after median, ulnar, and combined median-ulnar nerve injuries: A prospective study. J Plast Reconstr Aesthet Surg 2015;68:1-8.
Jaquet JB, Luijsterburg AJ, Kalmijn S, Kuypers PD, Hofman A, Hovius SE, et al.
Median, ulnar, and combined median-ulnar nerve injuries: Functional outcome and return to productivity. J Trauma 2001;51:687-92.
Roganovic Z. Missile-caused median nerve injuries: Results of 81 repairs. Surg Neurol 2005;63:410-8.
Allan CH. Functional results of primary nerve repair. Hand Clin 2000;16:67-72.
al-Ghazal SK, McKiernan M, Khan K, McCann J. Results of clinical assessment after primary digital nerve repair. J Hand Surg Br 1994;19:255-7.
Doezie AM, Lowe JB 3rd
, Hunter DA, Mackinnon SE. Effects of tobacco smoke on recovery after nerve crush injury in rats. Ann Plast Surg 2002;49:628-34.
Ruijs AC, Jaquet JB, Kalmijn S, Giele H, Hovius SE. Median and ulnar nerve injuries: A meta-analysis of predictors of motor and sensory recovery after modern microsurgical nerve repair. Plast Reconstr Surg 2005;116:484-94.
[Table 1], [Table 2], [Table 3]