Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-015-3626-4

KNEE

Intra‑articular peroneal nerve incarceration following multi‑ligament knee injury Amro Alhoukail1 · Anukul Panu2 · Jaret Olson3 · Nadr M. Jomha1 

Received: 27 February 2015 / Accepted: 28 April 2015 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2015

Abstract  Knee dislocation with a common peroneal nerve injury is a serious problem. A case of multi-ligamentous knee injury with the unusual and interesting finding of a common peroneal nerve rupture incarcerated within the knee joint is presented. MRI and arthroscopic images are used to document this occurrence. To date, there are no published reports of a similar finding in the English orthopaedic literature. Level of evidence IV. Keywords  Knee dislocation · Nerve incarceration · Multi-ligament knee injury · Common peroneal nerve injury

Introduction Knee dislocation is an uncommon but disabling injury requiring immediate attention and treatment. Associated injury can include fracture, ligamentous and neurovascular injury. Complications include ligamentous instability, loss of motion and persistent pain. Damage to the common peroneal nerve, although less well recognized than vascular * Nadr M. Jomha [email protected] 1

Division of Orthopaedic Surgery, Department of Surgery, 2D2.32 WMC University of Alberta Hospital, University of Alberta, Edmonton, AB T6G 2B7, Canada

2

Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Canada

3

Division of Plastic Surgery, Department of Surgery, University of Alberta, Edmonton, Canada





injury, has an overall incidence of 20–25 % [2]. It is important to note that in dislocations with disruption of the PCL and posterolateral corner the incidence of nerve injury is greater and may be as high as 45 % [10]. Presented here is an unusual case of a contact sport injury that resulted in a knee dislocation and peroneal nerve palsy with an intraoperative evidence of nerve entrapment in the knee joint.

Case report A 32-year-old male sustained a right knee dislocation while playing ball hockey (similar to ice hockey in the same confines but without ice and using a ball instead of a puck). He was running towards the ball and stopped quickly with his right leg moderately externally rotated. As he planted the right leg, his knee gave out without contact from another player. He stated he had to self-reduce the knee joint. He had significant swelling and pain in his right knee and was unable to ambulate. Upon admission to the emergency department, he was noted to have a swollen right knee with normal alignment. Ligamentous examination was difficult, but multi-plane laxity to the knee was noted (at the time of surgery, it was noted that there was anteroposterior laxity although not as great as expected from the MRI report and was greater in the anterior direction, while there was significant lateral laxity to varus stress and no medial laxity). Neurological examination revealed foot drop along with motor and sensory deficits in the distribution of the common peroneal nerve. Vascular exam revealed strong, palpable pulses to both posterior tibial and dorsalis pedis arteries with a normal ankle brachial index (ABI). Initial radiographs confirmed the joint was in reduced position. MRI (Fig. 1) revealed complete tears of both cruciate ligaments near their femoral attachments and extensive posterolateral

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Knee Surg Sports Traumatol Arthrosc

Fig.  1  a top left, b top right, c bottom left, d bottom right. Arrowheads in a (coronal proton density) and b (coronal inversion recovery) demonstrate a linear structure coursing beneath the posterior horn of the lateral meniscus and continuing around the fibular head. Circle outline in c (sagittal proton density) shows the fascicular configuration of the structure beneath the meniscus. Subsequent axial inversion recovery image in d shows that this structure continues around the fibular head, confirming it is the common peroneal nerve with high signal indicative of a post-traumatic neuritis

corner injuries including rupture of the lateral collateral ligament and biceps femoris tendon. Moreover, a fascicular structure was noted along the undersurface of the posterior horn of the lateral meniscus that was continuous with the common peroneal nerve at the fibular head. The common peroneal nerve could not be visualized above the joint line. The combination of these findings was suspicious for a common peroneal nerve transection. The patient was admitted to hospital, and a general consent for multiple ligament reconstruction using allograft tendon was obtained. Potential risks and complications explained to the patient included: nerve injury, vascular injury, compartment syndrome, amputation, infection, joint laxity, DVT causing death, joint stiffness and infection with hepatitis or HIV from allograft use. At surgery, knee arthroscopy confirmed rupture of cruciate ligaments (ACL, PCL), extensive posterolateral tissue damage (lateral collateral ligament, posterolateral corner, biceps femoris detachment) and a stable tear in the posterior horn of medial meniscus.

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Femoral condyle

Tibial plateau

Common peroneal nerve

Fig. 2  Arthroscopic picture with the grasper holding the nerve. This was the distal aspect of the common peroneal nerve that was transect and was entrapped underneath the lateral meniscus in the middle of the lateral compartment of the knee joint

Knee Surg Sports Traumatol Arthrosc

Interestingly, there was a strand of tissue that coursed from underneath the lateral meniscus into the lateral compartment of the knee joint (Figs. 2, 3). Arthroscopic visualization of the exposed end of the tissue showed nerve fibres indicating that this was the stump of the peroneal

nerve. This portion of the nerve was swept back under the lateral meniscus into the soft tissues until later exposure during open reconstruction of the lateral side of the joint. At the time of open reconstruction of the lateral collateral ligament and posterolateral corner, exploration along the course of the common peroneal nerve confirmed the arthroscopic finding and that the stand of tissue was the distal portion of the nerve. At this point, intra-operative consultation with a microvascular plastic surgeon at our institution was obtained and the conclusion was to tag the nerve and repair it at a later date to allow the nerve traction injury to fully demarcate to enable a repair using healthy nerve ends. In addition, this would allow time for the soft tissue injury to subside allowing the multiple ligament reconstruction time to heal and the knee to gain more normal function. The remainder of the surgical procedure was performed including ACL reconstruction using tibialis anterior allograft, PCL repair through femoral drill holes, lateral collateral ligament reconstruction using tibialis posterior allograft, posterolateral corner reconstruction using tibialis posterior allograft and biceps femoris tendon repair. A postoperative radiograph is seen in Fig. 4. Four months later, microsurgical nerve transfer was done using the lateral gastrocnemius branch of the tibial nerve to the deep branch of

Fig. 4  AP and lateral radiographs of the knee approximately 6 weeks post-multi-ligament reconstruction. The two ACL interference screws can be seen near the midline on the AP vertically oriented on both views. The horizontal tibial screw is fixation for the tibial limb of the posterolateral corner reconstruction. The barbed staple is augmentation of suture fixation for the femoral insertions of the lateral collat-

eral ligament and posterolateral corner ligament reconstructions. The fibular fixation of the lateral collateral ligament is through a drill hole in the fibular head with the ligament allograft sutured back on itself. The vascular clips mark the proximal end of the distal portion of the transected common peroneal nerve. This was for later identification during the nerve transfer

Femoral condyle Meniscus

Common peroneal nerve Tibial plateau

Fig. 3  With traction on the exposed nerve ending, the nerve could be seen to enter from the lateral-most portion of the joint and under the lateral meniscus

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the common peroneal nerve. Post-operatively, the patient was placed in a straight leg knee immobilizing brace for a period of 3 weeks to allow healing of the coaptation site and range of motion was started thereafter. Post-operatively from the ligament reconstruction, a physiotherapy protocol adapted from the protocol described in The multiple ligament injured knee: a practical guide to management by Gregory Fanelli [4] was instituted with some modifications. The patient was non-weight bearing while splinted in a bivalved cast that was removed for rehabilitation during the first 6 weeks. A graduated programme of increasing range of motion exercises and improving quadriceps/hamstring strength and proprioception and functional skills was performed although this had to be interrupted at approximately 4 months post-operatively for his nerve transfer. At the 10-month follow-up, the patient was ambulating without a knee brace although he was still wearing an ankle-foot orthosis for foot drop. He was still having a feeling of occasional instability but not frequent enough to wear a knee brace. He lacked approximately 10 degrees of knee flexion and had full extension. Subjective physical examination by the operating orthopaedic surgeon noted that there was grade I-combined anteroposterior laxity that was attributed more anterior than posterior. There was no posterolateral corner laxity, but there was grade II lateral collateral ligament laxity with a solid end point. There was no demonstrable peroneal nerve motor or sensory function at 6 months post-nerve transfer, but the patient had begun experiencing sharp pains radiating down into his foot.

Discussion The most important and interesting finding in this case report is that a transected common peroneal nerve was found incarcerated into the knee joint at the time of arthroscopic/open multi-ligament knee reconstruction after a knee dislocation. Three of the four reconstructed ligaments healed very well, while the lateral collateral ligament had grade II laxity at 10 months post-operatively. It is possible that the second surgery at 4 months post-ligament reconstruction could have had some effect on healing of the lateral collateral ligament reconstruction as the plastic surgeons had to go through the same lateral incision for the nerve transfer. Thus far, the nerve transfer has not generated any motor or sensory function in the common peroneal nerve distribution at only 6 months post-transfer although some nerve regeneration symptoms are felt by the patient. Traumatic dislocation of the knee joint is one of the most serious injuries of the lower extremity, and it can even compromise the viability of the limb. These injuries are rare, and it is likely that this contributes to the controversy

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Knee Surg Sports Traumatol Arthrosc

surrounding the management of ligament and neurovascular injuries [1, 8, 9]. Spontaneous reduction or reduction by emergency personnel may mask the severity of injury, making it hard to anticipate and prevent the complications that may ensue if the dislocation goes undetected [11, 12]. There have been few studies on the extent of nerve injury, the pattern of associated ligament injury and the exact prognosis for recovery. The incidence of common peroneal nerve palsies in most series is between 10 and 40 %, most of which were caused by a posterior dislocation. The common peroneal nerve is susceptible to injury because of its fixed attachment in the region of the neck of the fibula. The nerve proximal to this location is vulnerable to a traction injury when the knee is subjected to varus and hyperextension forces. Distal to the fibula, the superficial branch runs vertically downwards in the substance of peroneus longus, while the deep branch continues forwards horizontally between tibialis anterior and extensor digitorum longus where it is closely applied to the interosseous membrane. The deep branch may be more vulnerable to traction injury at the time of dislocation because of this latter relationship [3]. The anatomic status of the common peroneal nerve, subjected to violent traction during the dislocation, is the prime prognostic factor for spontaneous neurological remission. This is not always specified in the literature, often because nerve exploration and imaging may be lacking. Some authors perform systematic early exploration, while others explore the nerve only during lateral ligament repair [6]. Treatment of the nerve injury is difficult. Primary endto-end repair is not technically feasible in complete ruptures because of extensive fraying involving a considerable portion of the damaged ends. There may be a role for grafting the nerve in these cases at the time of the acute ligamentous reconstruction. Patients who regain no useful recovery can be considered for delayed nerve grafting. In a recent large study of injury to the peroneal nerve from a variety of causes, the results of nerve grafting were poor when grafts in excess of 6 cm were required [7]. Recent studies have supported the use of nerve transfer from a branch of the tibial nerve to gastrocnemius to reconstruct the peroneal nerve with improved outcomes [5]. The case presented here is unique in that the peroneal nerve was not only transected but also incarcerated inside the knee joint. To date, review of the English orthopaedic literature does not show a similar finding.

Conclusions Knee dislocation is a devastating injury, and common peroneal nerve palsy is a frequent association; however, intraarticular nerve incarceration is a very rare presentation that

Knee Surg Sports Traumatol Arthrosc

has not been reported in the English orthopaedic literature. Management of this problem is diverse and depends on many factors (timing, type of nerve injury, etc). Controversy exists with regard to the best surgical treatment outcome for complete transection of the nerve. Acknowledgments  There was no funding for this research.

References 1. Almekinders LC, Logan TC (1992) Results following treatment of traumatic dislocations of the knee joint. Clinic Orthop Relat Res 284:203–207 2. Becker EH, Watson JD, Dreese JC (2013) Investigation of multiligamentous knee injury patterns with associated injuries presenting at a level i trauma center. J Orthop Trauma 27(4):226–231 3. Deutsch A, Wyzykowski RJ, Victoroff BN (1999) Evaluation of the anatomy of the common peroneal nerve—defining nerve-atrisk in arthroscopically assisted lateral meniscus repair. Am J Sport Med 27(1):10–15 4. Fanelli GC (2004) Multiple ligament reconstruction rehabilitation. In: Fanelli GC (ed) The multiple ligament injured knee: a practical guide to management. Springer, New York, pp 211–212

5. Giuffre JL, Bishop AT, Spinner RJ, Shin AY (2012) Surgical technique of a partial tibial nerve transfer to the tibialis anterior motor branch for the treatment of peroneal nerve injury. Ann Plastic Surg 69(1):48–53 6. Johnson ME, Foster L, Delee JC (2008) Neurologic and vascular injuries associated with knee ligament injuries. Am J Sport Med 36(12):2448–2462 7. Kim DH, Murovic JA, Tiel RL, Kline DG (2004) Management and outcomes in 318 operative common peroneal nerve lesions at the Louisiana State University Health Sciences Center. Neurosurgery 54(6):1421–1428 8. Malizos KN, Xenakis T, Mavrodontidis AN, Xanthis A, Korobilias AB, Soucacos PN (1997) Knee dislocations and their management—a report of 16 cases. Acta Orthop Scand 68:80–83 9. Meyers MH, Harvey JP (1971) Traumatic dislocation of the knee joint—study of 18 cases. J Bone Jt Surg Am Vol A 53(1):16 10. Niall DM, Nutton RW, Keating JF (2005) Palsy of the common peroneal nerve after traumatic dislocation of the knee. J Bone Jt Surg Br 87B(5):664–667 11. Wascher DC, Becker JR, Dexter JG, Blevins FT (1999) Reconstruction of the anterior and posterior cruciate ligaments after knee dislocation—results using fresh-frozen nonirradiated allografts. Am J Sport Med 27(2):189–196 12. Wascher DC, Dvirnak PC, DeCoster TA (1997) Knee dislocation: initial assessment and implications for treatment. J Orthop Trauma 11(7):525–529

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Intra-articular peroneal nerve incarceration following multi-ligament knee injury.

Knee dislocation with a common peroneal nerve injury is a serious problem. A case of multi-ligamentous knee injury with the unusual and interesting fi...
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