https://doi.org/10.14517/aosm18005 Case Report pISSN 2289-005X·eISSN 2289-0068 Endoscopic excision of enlarged inflamed pes anserine bursa associated with auto-hamstring graft harvest for anterior cruciate ligament reconstruction Jin Kyu Lee1, Jae-Hyuk Yang2 1Department of Orthopedic Surgery, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, 2Department of Orthopedic Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea In this report, a case of enlarged inflamed pes anserine bursa in association with auto-hamstring graft harvest for ante- rior cruciate ligament reconstruction is presented. Complete removal of bursa sac was performed using the endoscopic procedure together with the post-tie screw removal procedure and second look arthroscopy. Keywords: Endoscopy; Bursa; Hamstring tendons; Anterior cruciate ligament reconstruction INTRODUCTION These muscles are primarily flexors of the knee and have a secondary internal rotational influence on the tibia, A bursa is a fluid-filled structure that is present between protecting the knee against rotatory as well as valgus the skin and tendon or tendon and bone. The main func- stress. The pes anserinus tendons are commonly used as tion of a bursa is to reduce friction between adjacent autografts in ligamentous reconstruction of the knees. moving structures [1,2]. Typically, bursae are located Donor site morbidities associated with hamstring ten- around large joints such as the shoulder, knee, hip, and don harvesting has been reported [4]. These include the elbow. Inflammation of this fluid-filled structure is called effect on hamstring and quadriceps strength, anterior bursitis. Trauma, infection, overuse, and hemorrhage knee pain and sensory deficits. Here, a case of enlarged are some of the common causes for inflammation [1,2]. inflamed pes anserine bursa in association with auto- Among several knee joint bursae, the pes anserine bursa hamstring graft harvest for anterior cruciate ligament is present at anteromedial aspect of knee joint and sepa- (ACL) reconstruction is presented. Complete removal of rates the pes anserine tendons, consisting of the distal bursa sac was performed using the endoscopic proce- sartorius, gracilis, and semitendinosus tendons, from the dure together with the post-tie screw removal procedure subjacent distal portion of the tibial collateral ligament and second look arthroscopy. The patient and his family and the bony surface of the medial tibial condyle [3]. were informed that the data concerning the case would The pes anserinus is composed of the combination of be submitted for publication and gave their consent. tendinous insertions of the sartorius, gracilis, and semi- tendinosus muscles. These three muscles attach to the CASE REPORT medial side of tibia to generate a shape reminiscent of a goose’s foot, which is the literal meaning of its name. A previous healthy 23-year-old man sustained ACL injury Received May 30, 2018; Revised August 1, 2018; Accepted August 9, 2018 Correspondence to: Jae-Hyuk Yang, https://orcid.org/0000-0001-8853-1997 Department of Orthopedic Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153 Gyeongchun-ro, Arthroscopy and Guri 11923, Korea. Tel: +82-31-560-2184, Fax: +82-31-557-8781, E-mail: [email protected] Orthopedic Sports Medicine Copyright © 2018 Korean Arthroscopy Society and Korean Orthopedic Society for Sports Medicine. All rights reserved. CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ AOSM by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 44 Arthrosc Orthop Sports Med 2018;5(2):44-47 Jin Kyu Lee, Jae-Hyuk Yang. Endoscopic excision of enlarged inflamed pes anserine bursa in his right knee which resulted from sports injury. He over previous incision area for tibial tunnel preparation underwent arthroscopic assisted single bundle ham- and post-tie screw fixation. There was no evidence of string autograft reconstruction using transtibial tech- knee joint effusion. Blood chemistries, including com- nique at another institution 2 years ago. From the past plete blood count, erythrocytes sedimentation rate, C- operation record, the preparation of auto-hamstring reactive protein, rheumatoid factors, and uric acid were gracilis and semitendinosus was followed by fixation of all within normal limits. Coronal and axial fat suppressed femoral side using two sleeves for the RigidFix cross pins T2-weighted magnetic resonance imaging (MRI) image, (DePuy Mitek, Raynham, MA, USA) and tibia fixation us- revealed well-demarcated, multi-lobulated cystic mass ing 10 mm × 25 mm bio-absorbable interference screw lesion with high signal intensity at subcutaneous area (Smith & Nephew, Andover, MA, USA). The tibia tunnel superficial to the pes anserine tendons (Fig. 1A, B). Based diameter was 10 mm. Post-tie washer screw fixation was on these findings, removal of post-tie screw with endo- performed to enhance tibia bone-tendon fixation. After scopic removal of cystic mass was scheduled in addition operation, the patient was follow up at local institution. to 2nd look intra-articular arthroscopic examinations. At 2-year follow-up, he had recovered well and returned The intra-articular arthroscopic examination revealed to his regular athletic activity. There was no difference in well tensioned with full synovial coverage of previously the mid-thigh circumference diameter compared to the reconstructed ACL. The overall evaluation was graded as contralateral limb. The International Knee Documenta- “A” according to Kondo and Yasuda classification [5]. No tion Committee objective score was grade A and Telos abnormal findings were found regarding the posterior stress radiographic unit (Telos, Weiterstadt, Germany) cruciate ligaments, and no tear was visualized in the me- measurement showed anteroposterior translation of 1 dial or lateral meniscus. mm more as compared with the contralateral uninjured With additional small incision at previous operation scar, knee. the post-tie screw was removed without difficulty. For However, besides the functional status regarding ACL removal of the palpable mass, subcutaneous stab inci- reconstruction, the patient visited our clinic complain- sion was made through the incision which was made for ing palpable mass at anteromedial aspect and medial removing the post-tie screw. By introducing the 4 mm aspect pain during flexion and extension. The mass was arthroscope through this incision, the bursa sac was treated conservatively at local clinic (including steroid identified (Fig. 2A). Additional so-called “bursa portal” injection) but recurred. A physical examination revealed was made at the distal edge of the sac to introduce the a palpable, tender, soft tissue mass of about 4 cm × 5 cm arthroscopic shaver. Complete removal of the bursa sac A B C Fig. 1. Coronal and axial fat suppressed T2-weighted magnetic resonance imaging image, revealed well-demarcated, multi-lobulated cystic mass lesion with high signal intensity at subcutaneous area superficial to the pes anserine tendons. Coronal (A), sagittal (B), and axial image (C). www.e-aosm.org 45 Jin Kyu Lee, Jae-Hyuk Yang. Endoscopic excision of enlarged inflamed pes anserine bursa Fig. 2. (A) Clinical intraoperative photo showing the location of mass. Viewing portal was made through the incision made for post-tie screw removal (white arrow). By introducing the 4 mm arthro- scope through this incision, the bursa sac was identified. Notice the cystic portal where endoscopic shaver was in- troduced (black arrow). (B) Endoscopic image showing the bursal sac. Complete A B removal of the bursa sac was performed by direct endoscopic visualization. tendinosus muscles. These three muscles attach to the medial side of tibia to generate a shape reminiscent of a goose’s foot, which is the literal meaning of its name. These muscles are primarily flexors of the knee and have a secondary internal rotational influence on the tibia, protecting the knee against rotatory as well as valgus stress. The pes anserinus tendons are commonly used as autografts in ligamentous reconstruction of the knees. Inflammation of the conjoined insertion of the sartorius, gracilis and semitendinosus muscles along the proximal medial aspect of the tibia is recognized as pes anserine bursitis. Patients with pes anserine bursitis may present with classic symptoms of tenderness and swelling along the proximal medial tibia or may complain of vague Fig. 3. Histologic section of the bursa wall. The specimen shows a loose- medial knee pain, which may mimic medial meniscal ly arranged spindled cell proliferation with fibrous tissue (H&E, ×100). or tibial collateral ligament injury. Although the gracili- tis and semitendinosus tendons were harvested in the was performed by direct endoscopic visualization (Fig. index operation, pes anserine bursitis may occur after 2B). Biopsy was performed (Fig. 3). Compressive dressing autograft harvest procedure, as demonstrated in this re- was applied and full weight bearing was permitted on the port. Although it may be a minor side effect after surgery, next day after operation. No recurrence of the mass was patients for ACL reconstruction procedure should be ex- observed after 1-year follow-up. plained during preoperative surgical informed consent. Surgical