Journals | Policy | Permission

Journal of Current Surgery

Review

Volume 7, Number 1-2, June 2017, pages 1-3

Erectile Dysfunction Secondary to Pudendal Nerve Injury Complicating Orthopedic Surgery: Practical Recommandations

Erectile dysfunction (ED) resulting from direct damage of pudendal nerve involved following orthopedic surgery is not uncommon; it can have serious medico-legal implications in addition being a distressful event for the patients. Excessive and/or prolonged traction against the perineal post of a traction table, leading to direct compression and localized ischemia to the nerve are the main contributing factors of injury. The relevant anatomy, etiopathogenesis and management are discussed, and suggestions are made for its prevention.

The pudendal nerve originates in the sacral plexus; it derives its fibers from the ventral rami of the second, third and fourth sacral nerves. It passes between the piriformis muscle and coccygeus (ischiococcygeus) muscles and leaves the pelvis through the lower part of the greater sciatic foramen. It crosses posterior to the ischial spine and reenters the pelvis curving anteriorly and inferiorly through the lesser sciatic foramen. It accompanies the internal pudendal artery and internal pudendal vein upwards and forwards along the lateral wall of the ischiorectal fossa, being contained in a sheath of the obturator fascia termed the pudendal canal (Alcock’s canal), along with the internal pudendal blood vessels [1]. The pudendal nerve when it emerges from the pudendal canal branches into the deep perineal nerve and the dorsal nerve of the penis. Sensory inputs are centrally integrated as sensory perceptions and elicit autonomic and somatomotor responses, including perineal floor muscle contraction, through the dorsal nerve of the penis. Conversely, the perineal nerve supplies the largest percentage of scrotum sensation, together with motor branches that innervate part of the levatoris ani muscle, as well as the bulbocavernous and ischiocavernous muscles. Thus, the integrity of the perineal nerve is essential to the ischiocavernous muscle contractions that produce optimal rigidity and maintenance of erection [2].

As a whole, the pudendal nerve is a mixed nerve of critical importance to all aspects of erection that can be readily contused between the perineal post of the fracture table and the bony ridge of the ischial ramus and the dense fascia of the urogenital diaphragm [3, 4].

The reported incidence of pudendal nerve injury during orthopedic trauma surgery ranges from 1.9% to 27.6% and is closely associated to the use of traction tables [5, 6]. Mallet et al [7] reviewed 168 patients, with femoral and tibial fractures treated with intramedullary nails on traction tables and found that the incidence of ED was as high as 40.5%. Pudendal nerve palsy has been reported as a complication following hip arthroscopy [8].

Prolonged countertraction on the fracture table and the inappropriate placement of the perineal post, leading to contusion or stretching of the pudendal nerve, are the two main contributing factors of postoperative palsy [5, 9-11].

A relationship was demonstrated between the duration and magnitude of intraoperative traction and the development of pudendal nerve palsy during intramedullary femoral fracture fixation. Rudge et al [12] have shown that continuous pressure of 1.4 kg/cm for 90 min can cause a nerve conduction block, which can be complete and permanent. It has been estimated that the actual traction pressure exerted on the perineal region to be greater than 1.4 kg/cm, placing the perineal nerves involved in the erectile mechanism at considerable risk of injury [10, 13]. The mean operative time in the literature varies between 130 and 240 min and is regarded by some authors as a risk factor [13, 14].

Several studies showed a correlation between the prevalence of pudendal nerve injury and the perineal post diameter [7, 9, 10, 13, 14]. It was always smaller than the average distance separating the two ischial tuberosities in male adults (8 - 10 cm). This can increase the pressure on the bony prominence of the ischial ramus, the precise location of the dorsal nerve of the penis. The highest incidence was reported by Rose et al [14] who used a post of 3.8 cm in diameter.

Insufficient muscle relaxation was also reported to be a contributing factor of pudendal nerve injury. Mallet et al [7] reported that greater intraoperative doses of curare significantly decrease the incidence of postoperative ED, suggesting that postoperative ED could be partially prevented by optimal muscle relaxation during fracture reduction. This is particularly important in young men who have strong femoral muscles and thus require larger traction forces when compared to elderly patients with femur fractures.

The sensory terminal branches of the pudendal nerve appear more susceptible to injury than do the motor branches which control sexual function. This explains that in 90% of cases, it is a simple contusion (neurapraxis) of the pudendal nerve due to stretching or simple compression. Clinical signs are essentially sensitive, such as hypoesthesia of the perineum, and will amend rapidly in 4 weeks [15]. More rarely it is a severe contusion or crushing of the nerve (neurotmesis) which is accompanied by clinical and electrical signs of denervation. Vesico-sphincter dysfunction, such as urinary incontinence, ED and hypoesthesia or complete anesthesia of scrotum and glans penis are the main clinical manifestations. Functional recovery is longer of the order of 6 months [16, 17].

Perineal electrophysiological examination can confirm the pudendal neuropathy and give prognostic information. Bulbocavernosus muscle electromyography (EMG), measurements of the bulbocavernosus reflex latencies, somatosensory evoked potentials of the pudendal nerve, sensory conduction velocity of the dorsal nerve of the penis, and pudendal nerve terminal motor latencies were used to objective the pudendal nerve palsy. They should be considered when symptoms are not regressive and in cases of vesico-sphincter dysfunction and immediate severe ED [18].

No medical treatment has demonstrated its effectiveness. Sildenafil, tadalafil and vardenafil are the phosphodiesterase inhibitors licensed for the treatment of ED. The agents may be stopped after the erectile capacity returns to normal, or to a level where the patient feels it is satisfactory, and this may range from few months in some patients to a longer term in others. Pudendal nerve decompression through para-anal or perineal incision was reported in some cases of stable disorders [16, 19].

Strategies to avoid perineal traction injuries include using a well-padded, large diameter perineal post (˃ 10 cm) to distribute traction on the perineum. This should be placed between the genitalia and the atraumatic lower limb in order to keep tilting of the traumatized side of the pelvis to a minimum against the perineal post [13, 20, 21]. The duration of traction time should be minimized; traction should be limited to the critical operative steps only. For example, in the case of intramedullary nail fixation, traction should be used during the reduction manoeuvre, the passage of the guide wire and nail across the fracture site and the placement of the interlocking screws. Traction should be released for the rest of the procedure, in order to reduce the amount and duration of intra-operative traction. When the surgical time exceeds 120 min, the intraoperative traction should be released; periodic release of the traction should, also, be considered [12, 15, 20]. Complete muscle relaxation under anesthesia is essential to reduce muscle tone, which will be advantageous in reducing the force needed during intraoperative traction. This is particularly important in young men who have strong femoral muscles and thus require larger traction forces when compared to elderly patients with femur fractures [7].

ED secondary to pudendal nerve injury after femur orthopedic surgery is common. Surgeons should be aware of the pathogenesis behind the development of this injury and absolute care needs to be taken during operation to avoid it from happening. Iatrogenic ED can have serious medico-legal implications, therefore, patients must be clearly informed about this possible neurological complication before an operation on the orthopedic table.

Conflicts of Interest

The authors have none to declare.

1. Grant's Atlas of Anatomy,11th ed. p. 221.
2. Robert R, Prat-Pradal D, Labat JJ, Bensignor M, Raoul S, Rebai R, Leborgne J. Anatomic basis of chronic perineal pain: role of the pudendal nerve. Surg Radiol Anat. 1998;20(2):93-98.
   doi pubmed
3. Giuliano F, Rampin O, Jardin A, Rousseau JP. Electrophysiological study of relations between the dorsal nerve of the penis and the lumbar sympathetic chain in the rat. J Urol. 1993;150(6):1960-1964.
   pubmed
4. Rampin O, Gougis S, Giuliano F, Rousseau JP. Spinal Fos labeling and penile erection elicited by stimulation of dorsal nerve of the rat penis. Am J Physiol. 1997;272(5 Pt 2):R1425-1431.
   pubmed
5. France MP, Aurori BF. Pudendal nerve palsy following fracture table traction. Clin Orthop Relat Res. 1992;276:272-276.
6. Mei-Dan O, McConkey MO, Young DA. Hip arthroscopy distraction without the use of a perineal post: prospective study. Orthopedics. 2013;36(1):e1-5.
   doi pubmed
7. Mallet R, Tricoire JL, Rischmann P, Sarramon JP, Puget J, Malavaud B. High prevalence of erectile dysfunction in young male patients after intramedullary femoral nailing. Urology. 2005;65(3):559-563.
   doi pubmed
8. Byrd JW. Hip arthroscopy utilizing the supine position. Arthroscopy. 1994;10(3):275-280.
   doi
9. Letts M, Jarvis J, Lawton L, Davidson D. Complications of rigid intramedullary rodding of femoral shaft fractures in children. J Trauma. 2002;52(3):504-516.
   doi
10. Schulak DJ, Bear TF, Summers JL. Transient impotence from positioning on the fracture table. J Trauma. 1980;20(5):420-421.
    doi pubmed
11. Riew KD, Sturm PF, Rosenbaum D, Robertson WW, Jr., Yamaguchi K. Neurologic complications of pediatric femoral nailing. J Pediatr Orthop. 1996;16(5):606-612.
    doi pubmed
12. Rudge P. Tourniquet paralysis with prolonged conduction block. An electro-physiological study. J Bone Joint Surg Br. 1974;56-B(4):716-720.
    pubmed
13. Lindenbaum SD, Fleming LL, Smith DW. Pudendal-nerve palsies associated with closed intramedullary femoral fixation. A report of two cases and a study of the mechanism of injury. J Bone Joint Surg Am. 1982;64(6):934-938.
    doi pubmed
14. Rose R, Chang S, Felix R, Adams P, Juste S St., Fletcher C, et al. Pudendal nerve palsy following static intramedullary nailing of the femur. Internet J Orthop Surg. 2008;10(1).
15. Brumback RJ, Ellison TS, Molligan H, Molligan DJ, Mahaffey S, Schmidhauser C. Pudendal nerve palsy complicating intramedullary nailing of the femur. J Bone Joint Surg Am. 1992;74(10):1450-1455.
    doi pubmed
16. Shafik A. Pudendal canal decompression in the treatment of erectile dysfunction. Arch Androl. 1994;32(2):141-149.
    doi pubmed
17. Kao JT, Burton D, Comstock C, McClellan RT, Carragee E. Pudendal nerve palsy after femoral intramedullary nailing. J Orthop Trauma. 1993;7(1):58-63.
    doi pubmed
18. Amarenco G, Ismael SS, Bayle B, Denys P, Kerdraon J. Electrophysiological analysis of pudendal neuropathy following traction. Muscle Nerve. 2001;24(1):116-119.
    doi
19. Lyon T, Koval KJ, Kummer F, Zuckerman JD. Pudendal nerve palsy induced by fracture table. Orthop Rev. 1993;22(5):521-525.
    pubmed
20. Topliss CJ, Webb JM. Interface pressure produced by the traction post on a standard orthopaedic table. Injury. 2001;32(9):689-691.
    doi
21. Kruger DM, Kayner DC, Hankin FM, Falahee MH, Kaufer H, Matthews LS, Goldstein SA. Traction force profiles associated with the use of a fracture table: a preliminary report. J Orthop Trauma. 1990;4(3):283-286.
    doi pubmed

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial 4.0 International License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Journal of Current Surgery is published by Elmer Press Inc.