Isolated Popliteus Muscle Rupture with Neurovascular Compression Requiring Surgical Decompression

(aspects of trauma • a case report)

Isolated Popliteus Muscle Rupture With Neurovascular Compression Requiring Surgical Decompression

Matthew Bollier, MD, Todd Ream, MD, and Gregory Hodgman, MD

he tibial nerve, poplite- We report the unique case of an Case Report al artery, and popliteal isolated popliteus muscle rupture A 34-year-old police officer pre- vein are superficial to the that led to compression of the tibial sented to the emergency depart- Tpopliteus muscle as they nerve in the popliteal fossa requir- ment with a 2-day history of excru- exit the popliteal fossa deep to ing surgical decompression. ciating posterior left knee pain. the fibrous soleus arch (Figure 1). The popliteus muscle forms the He described a twisting injury to There are 9 case reports of tibial floor of the popliteal fossa cours- his flexed left knee while helping a nerve compression in the popli- ing obliquely across the posterior motorist change a tire 2 weeks prior. teal fossa with etiologies includ- tibia with a tendinous insertion on There was an immediate onset of ing popliteus muscle rupture, mass the lateral femoral condyle anterior posterior knee pain, but it resolved lesion, or anomalous course of the and inferior to the lateral collateral over several hours. During the 2 gastrocnemius.1-9 When masses, ligament insertion.10-13 The poplit- days prior to emergency depart- fibrous bands, or swelling com- eus muscle functions as the primary ment evaluation, he reported wors- press the nerve and vein against the internal rotator of the tibia, unlock- ening posterior leg pain, weakness, rigid soleus arch, clinical symptoms ing the knee during early flexion.14-15 and an inability to bear weight. develop. There are 4 case reports It also is a static and dynamic stabi- Right knee and tibia/fibula radio- of a popliteus muscle injury caus- lizer of the lateral side of the knee. graphs showed no fracture or bony ing tibial nerve palsy, but surgical Although most popliteus injuries decompression of this problem has are part of a complex posterolateral not been described previously.1-4 corner knee injury, isolated tendon avulsions and muscle belly rup- Dr. Bollier is Assistant Professor, tures have been described.1-10,16-20 Department of Orthopaedic Surgery, In this case, an isolated poplit- University of Iowa, Iowa City, Iowa. He eus muscle rupture from a knee was Orthopaedic Surgery Resident, external rotation injury caused Michigan State University, Kalamazoo Center for Medical Studies, Kalamazoo, an inflammatory mass effect in Michigan, at the time the article was the popliteal fossa, compressing written. the tibial nerve against the soleus Dr. Ream is Orthopaedic Surgeon, arch leading to a progressive tibial Kalamazoo Orthopaedic Clinic, and nerve palsy and multiple deep vein Clinical Assistant Professor, Michigan State University, Kalamazoo, Michigan. thrombosis (DVT). This interest- Dr. Hodgman is Radiologist, Advanced ing case report demonstrates the Radiology Services P.C., Kalamazoo, anatomy of the posterior aspect of Michigan. the knee, highlights the importance of a thorough physical exam and Address correspondence to: Matthew Bollier, MD, Department of Orthopaedic advanced imaging techniques, and Surgery, University of Iowa Hospitals and reviews the current literature on Figure 1. Popliteal fossa anatomy. The Clinics, 2701 Prairie Meadow Dr, Iowa neurovascular compression after a tibial nerve, popliteal artery, and popli- City, IA 52242 (tel, 319-467-8254; e-mail, popliteus muscle rupture. teal vein are visualized directly super- [email protected]). The authors have obtained the ficial to the popliteus muscle as they course distally under the soleus arch. Am J Orthop. 2010;39(12):588-591. patient’s written informed consent Abbreviations: a, artery; m, muscle; Copyright Quadrant HealthCom Inc. for print and electronic publication n, nerve; v, vein. Figure 1 provided by 2010. All rights reserved. of the case report. Matthew Morrey.

588 The American Journal of Orthopedics® M. Bollier et al

Figure 2. Patient presented to the emergency room with a large effusion of the left knee.

abnormalities. Laboratory analysis Figure 3. T1-weighted sagittal magnetic resonance imaging of left knee after intrave- revealed an erythrocyte sedimenta- nous gadolinium reveals popliteus muscle enlargement with no enhancement, and edema posterior to the muscle. tion rate of 55 mm/h, C-reactive protein of 13.5 nmol/L, and a white blood cell count of 10.9×109/L. After the emergency department evaluation, the orthopedic surgery service was consulted. Initial questioning revealed a burning posterior knee pain that radiated distally along the posterior left leg, plantar foot dysesthesias, and a knee effusion. The patient had an elevated temperature (38.5°C). He appeared anxious and couldn’t find a comfortable position. He had a large knee effusion and painless passive knee range of motion from Figure 4. T1-weighted coronal magnetic resonance imaging of left knee after intrave- 0° to 45° (Figure 2). Posterolateral nous gadolinium shows popliteus muscle hypertrophy with no enhancement. calf swelling and tenderness were present, and the patient reported revealed a white blood cell count on therapeutic enoxaparin (1 mg/ posterior leg discomfort with pas- of 10.0×109/L, normal glucose and kg) to treat DVT and was admitted sive ankle dorsiflexion and resisted lactate dehydrogenase levels, and to the hospital for observation and ankle plantarflexion. There was no organism present with bacte- pain control. decreased sensation to light touch rial cultures. A lower-extremi- Eighteen hours after admission, and pinprick on the lateral plantar ty ultrasound showed deep vein the patient required an increased foot. The gastrocnemius and soleus thrombosis in the anterior tibial, amount of intravenous pain med- muscles showed grade 5/5 strength deep peroneal, and posterior tibial ications and reported worsening by manual muscle testing, but flex- veins. Magnetic resonance imag- posterior leg pain. Examination or hallucis longus muscle strength ing (MRI) with intravenous gado- revealed decreased sensation to was grade 3/5. The remainder of linium of the left knee and left light touch and pinprick involving the neurovascular examination calf demonstrated popliteus muscle the entire plantar foot. Manual was normal. Knee stability testing swelling with no enhancement and muscle testing showed grade 0/5 showed symmetric findings com- surrounding edema (Figures 3–5). flexor hallucis longus strength and pared to the contralateral knee with The MRI findings were consistent grade 2/5 gastrocnemious and sole- the Lachman test, posterior drawer with a popliteus muscle rupture us strength. The patient’s posterior test, varus/valgus stress test, and and subsequent necrosis. An asso- calf compartment was soft but dif- Dial test. There was no erythema, ciated inflammatory mass effect fusely tender to palpation. He had fluctuance, or wounds. Calf com- and popliteus muscle swelling com- increased discomfort with passive partments were soft. pressed the nerve and vein against ankle dorsiflexion. A knee aspiration was performed the fibrous soleus arch leading to The patient was felt to have a and 30 mL of clear yellow fluid an acute tibial neuropathy and mul- progressive tibial neuropathy and was obtained. Laboratory analysis tiple DVT. The patient was started urgent surgical decompression was

December 2010 589 Isolated Popliteus Muscle Rupture With Neurovascular Compression planned. He was placed in a prone position for a posterior approach to the knee. A lazy S-shaped incision was made, curving from distal medial to proximal lateral. After dissecting down to the fascia, the sural nerve and small saphenous vein were identified and traced proximally. The fascia was split in line with the incision, and the dissection proceeded between the medial and lateral heads of the gastrocnemius muscle. The tibial nerve was identified and found to be pale, atrophic, and flattened at Figure 5. T1-weighted axial magnetic resonance imaging of left knee after intravenous the soleus arch (Figure 6). The gadolinium reveals popliteus muscle enlargement with no enhancement, and edema posterior to the muscle. soleus arch was divided longitudinally to decompress the nerve and vein. Necrotic-appearing popliteus muscle was débrided (Figure 7). The skin was closed, and the patient’s leg was placed in a soft dressing. The patient was made non–weight bearing for 2 weeks and knee range of motion was limited to 45° of flexion. The neuropathic pain resolved immediately after surgery. Postoperative vascular surgery consultation was obtained, and the Figure 6. The patient is in the prone Figure 7. Popliteal fossa. The soleus patient was started on a 3-month position for posterior approach to the arch is divided longitudinally and the course of coumadin to treat DVT. left knee. The tibial nerve is pale, atro- necrotic popliteus muscle is débrided. phic, and compressed at the soleus At 2 weeks, weight bearing and knee arch. range of motion were progressed. full active knee range of motion At 2 months, the patient had full mon, limited to various case with no knee effusion, ligamentous knee range of motion and ambulat- reports.1-10,16-20 Most popliteus laxity, or mechanical symptoms. ed independently. He still reported muscle injuries are part of a multi- Conservative treatment involves decreased plantar foot sensation. ligament knee injury involving the injections, quadriceps strengthen- He had grade 4/5 gastrocnemius posterolateral corner.21 Less than ing, stretching, and rest. muscle strength and grade 1/5 flexor 10% of popliteus muscle injuries Popliteus tendon avulsion is hallucis longus muscle strength. He are isolated.16,22 Several patterns of more common than muscle belly was able to return to active duty as isolated popliteus injury have been injuries and typically involves a a police officer. described: a tendon avulsion or sudden external rotation force to a At 9 months, medial plantar sen- rupture, muscle belly rupture, or partially flexed knee.16 These avul- sation had returned, but the patient popliteus tendinitis. The diagno- sions usually are associated with still reported numbness on the lat- sis of an isolated popliteus injury a posterolateral corner ligament eral plantar foot. He had grade requires a thorough history, physi- injury, so it is essential to perform 5/5 ankle plantar flexion strength cal examination, and appropriate a detailed knee exam. Patients with and grade 1/5 flexor hallucis longus diagnostic imaging to check for isolated tendon avulsions will have muscle strength. He was able to associated injuries.2,22 a stable knee and similar physical ambulate with a normal gait and to Popliteus tendinitis has been examination findings to those with continue working as a police officer. described in athletes who present popliteus tendinitis . Diagnosis can with chronic posterolateral knee be confirmed with MRI or lack of pain.14 Posterolateral joint line visualization of the popliteus ten- Discussion tenderness and pain with resisted don during arthroscopy.16,23 An iso- Isolated injuries to the poplit- internal rotation of the leg often are lated popliteus muscle belly rupture eus muscle are extremely uncom- present. Patients typically display occurs with a similar mechanism of 590 The American Journal of Orthopedics® M. Bollier et al injury, but patients are more likely an isolated popliteus muscle rup- Popliteus strain causing tibial nerve palsy with a permanent partial deficit: a case report. Am J to demonstrate an acutely painful ture. Surgical decompression was Sports Med. 2006;34(7):1176-1180. swollen calf.3,4 chosen because of the progressive 3. Geissler WB, Corso SR, Caspari RB. Isolated rupture of the popliteus with posterior tibial nerve Isolated tibial nerve lesions are neurologic deficit and increasing palsy. J Bone Joint Surg Br. 1992;74(6):811-813. rare and typically are located in the neuropathic pain over a 24-hour 4. Bowditch MG, Kay NR. Painful swollen calf due to isolated rupture of popliteus. Injury. tarsal tunnel posterior to the medi- period. As in acute carpal tunnel 1994;25(3):200-201. al malleolus. A review of the litera- syndrome, the tibial nerve is com- 5. Iida T, Kobayashi M. Tibial nerve entrapment at the tendinous arch of the soleus: a case report. ture revealed only 9 cases of tibial pressed in a confined area. With Clin Orthop. 1997;(334):265-269. 6. Saal JA, Dillingham MF, Gamburd RS, Fanton nerve palsy in the popliteal fossa: acute carpal tunnel syndrome, GS. The pseudoradicular syndrome. Lower 5 cases of atraumatic compression urgent decompression is thought to extremity peripheral nerve entrapment masquer- ading as lumbar radiculopathy. Spine (Phila Pa and 4 cases of traumatic popliteus minimize permanent nerve damage 1976). 1988;13(8):926-930. injury.1-9 The tibial nerve lies super- and motor and sensory deficits.24-25 7. Podore PC. Popliteal entrapment syndrome: a report of tibial nerve entrapment. J Vasc Surg. ficial and lateral to the popliteal An isolated popliteus muscle 1985;2(2):335-336. artery and vein as it enters the pop- rupture is a rare injury, but it may 8. Ekelund AL. Bilateral nerve entrapment in the popliteal space. Am J Sports Med. liteal fossa. It provides innervation be associated with an inflamma- 1990;18(1):108. for the gastrocnemius, soleus, and tory mass effect that compresses 9. Psathakis D, Psathakis N. Popliteal compression syndrome: an overproportional incidence popliteus muscles before passing the tibial nerve against the fibrous [in German]. Vasa. 1991;20(3):256-260. deep to the fibrous soleus arch.2 As soleus arch. Although previous 10. LaPrade RF, Morgan PM, Wentorf FA, Johansen S, Engebretsen L. The anatomy of the posterior the nerve dives deep to the soleus reports have recommended nonop- aspect of the knee. An anatomic study. J Bone arch, it lies directly posterior to the erative treatment, our patient had Joint Surg Am. 2007; 89(4):758-764. 11. Rose DJ, Parisien JS. Popliteus tendon rupture. popliteus muscle and is at risk for documented progressive neurologic Case report and review of the literature. Clin compression (Figure 1). decline. Urgent surgical decompres- Orthop. 1988;(226):113-117. 12. Stäubli HU, Birrer S. The popliteus tendon There have been several reports of sion allowed full functional recov- and its fascicles at the popliteal hiatus: gross atraumatic tibial nerve compression ery and immediately relieved his anatomy and functional arthroscopic evaluation with and without anterior cruciate ligament defi- in the popliteal fossa secondary to neuropathic pain. However, he was ciency. Arthroscopy. 1990;6(3):209-220. mass lesion, gastrocnemius hyper- left with a permanent partial neu- 13. Alpert JM, McCarty LP, Bach BR Jr. The direct posterior approach to the knee: surgi- trophy, fibrous bands, or anomalous rologic deficit with lateral plantar cal and anatomic approach. J Knee Surg. gastrocnemius fibers.5-9 In one case, foot numbness and flexor hallucis 2008;21(1):44-49. 14. Petsche TS, Selesnick FH. Popliteus tendini- surgical decompression of the soleus longus muscle weakness. tis: tips for diagnosis and management. Phys arch was performed for an atrau- Sports Med. 2002;30(8):27-31. 15. Mann RA, Hagy JL. The popliteus muscle. matic tibial nerve palsy secondary Conclusion J Bone Joint Surg Am. 1977;59(7):924-927. to a popliteus muscle lesion.5 As in Based upon this single case report, 16. Guha AR, Gorgees KA, Walker DI. Popliteus tendon rupture: a case report and review of the our case, neuropathic pain resolved we are unable to conclude wheth- literature. Br J Sports Med. 2003;37(4):358-360. immediately and near full neuro- er surgical intervention leads to 17. Naver L, Aalberg JR. Avulsion of the popliteus tendon. A rare cause of chondral frac- logic recovery was obtained. superior results than nonoperative ture and hemarthrosis. Am J Sports Med. There have been 4 case reports of treatment in cases that present with 1985;13(6):423-424. 18. Winge S, Phadke P. Isolated popliteus muscle traumatic tibial nerve palsy second- stable tibial nerve injuries. However, rupture in polo players. Knee Surg Sports ary to a popliteus muscle rupture.1-4 when progressive neurologic deteri- Traumatol Arthrosc. 1996;4(2):89-91. 19. Mirkopulos N, Myer TJ. Isolated avulsion of the Each of these cases shared a similar oration is noted, surgical intervention popliteus tendon. A case report. Am J Sports mechanism of injury and physi- can produce immediate neuropath- Med. 1991;19(4):417-419. 20. Burstein DB, Fischer DA. Isolated avulsion of cal examination with our case. All ic pain relief and improvement of the popliteus tendon in a professional athlete. cases involved some plantar senso- tibial nerve function. Arthroscopy. 1990;6(3):238-241. 21. Laprade RF, Gilbert TJ, Bollom TS, Wentorf F, ry deficit, and 3 cases reported toe Chaljub G. The magnetic resonance imaging flexion and ankle plantar flexion Authors’ Disclosure appearance of individual structures of the posterolateral knee. A prospective study of normal weakness. Unlike the present case, Statement knees and knees with surgically verified grade III each patient was treated nonop- The authors report no actual or injuries. Am J Sports Med. 2000;28(2):191-199. 22. Brown TR, Quinn SF, Wensel JP, Kim JH, Demlow eratively. Two of these patients had potential conflict of interest in rela- T. Diagnosis of popliteus injuries with MR imaging. complete neurologic recovery and 2 tion to this article. Skeletal Radiol. 1995;24(7):511-514. 23. Fineberg MS, Duquin TR, Axelrod JR. patients had minor neurologic defi- Arthroscopic visualization of the popliteus ten- cits at long-term follow-up. References don. Arthroscopy. 2008;24(2):174-177. 1. de Ruiter GC, Torchia ME, Amrami KK, Spinner 24. Ford DJ, Ali MS. Acute carpal tunnel syndrome. The present case is the first RJ. Neurovascular compression following iso- Complications of delayed decompression. account of surgical decompres- lated popliteus muscle rupture: a case report. J Bone Joint Surg Br. 1986;68(5):758-759. J Surg Orthop Adv. 2005;14(3):129-132. 25. Schnetzler KA. Acute carpal tunnel syndrome. sion for tibial nerve palsy after 2. Ortiguera CJ, Bremner BR, Peterson JJ. J Am Acad Orthop Surg. 2008;16(5):276-282.

This paper will be judged for the Resident Writer’s Award

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