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Arthroscopic Excision of Ganglion Cysts of the Posterior Cruciate Ligaments Using Posterior Trans-Septal Portal
Arthroscopic Excision of Ganglion Cysts of the Posterior Cruciate Ligaments Using Posterior Trans-Septal Portal Tsung-Ying Tsai, M.D., Yu-Sheng Yang, M.D., Feng-Jen Tseng, M.D., Kun-Yi Lin, M.D., Che-Wei Liu, M.D., Hsain-Chung Shen, M.D., Chian-Her Lee, M.D., Leou-Chyr Lin, M.D., and Ru-Yu Pan, M.D., Ph.D.
Purpose: To evaluate clinical outcomes of arthroscopic excision of ganglion cysts involving the posterior cruciate ligament (PCL) using the posterior trans-septal portal in the knee. Methods: A retrospective study was performed of 15 cases of ganglion cyst involving the PCL treated at our institution over a period of 4 years. All the cysts were diagnosed and had their location confirmed preoperatively by magnetic resonance imaging (MRI). All the cysts were excised arthroscopically through the posterior trans-septal portal. All patients were followed up with MRI evaluation at a mean of 36 months after surgery. In addition, International Knee Documentation Committee (IKDC) scores and range of motion (ROM) were obtained preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes. Results: Most of the patients were male patients, and the mean age was 32 years. The most common presenting complaint was pain and difficulty in knee flexion. Preoperatively, the mean ROM was 3° to 110° and the mean IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 patient (7%). After surgery, MRI evaluation at a mean follow-up time of 36 months showed no cyst recurrence. Postoperatively, the mean IKDC score was 91 (range, 70 to 99; SD, 9.3) and the mean ROM was 3° to 128°. Conclusions: Ganglion cysts associated with the PCL can cause knee pain and limitation of knee flexion. MRI evaluation is a noninvasive method of diagnosing PCL ganglion cysts. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence. Level of Evidence: Level IV, therapeutic case series.
G
anglion cysts are benign lesions arising from the joint capsule or tendon sheath and contain mucinous fluid. Intra-articular ganglia of the knee
From the Department of Orthopedics, Tri-Service General Hospital, National Defense Medical Center (T-Y.T., Y-S.Y., K-Y.L., C-W.L., H-C.S., L-C.L., R-Y.P.), Taipei; Department of Orthopedics, Hualien Armed Forces General Hospital (T-Y.T., F-J.T.), Hualien; and Department of Orthopedics, Taipei Medical University (C-H.L.), Taipei, Taiwan. The authors report no conflicts of interest. Received February 21, 2011; accepted July 19, 2011. Address correspondence to Ru-Yu Pan, M.D., Ph.D., Department of Orthopedics, Tri-Service General Hospital, National Defense Medical Center 325, Cheng-Kung Road Section 2, Taipei 114, Taiwan. E-mail: [email protected] Crown Copyright © 2012 Published by Elsevier Inc. on behalf of the Arthroscopy Association of North America. All rights reserved. 0749-8063/11117/$36.00 doi:10.1016/j.arthro.2011.07.013
are unusual lesions and may produce clinical manifestations such as knee pain and limitation of knee flexion mimicking internal derangement. Ganglion cysts originating from the posterior cruciate ligament (PCL) are relatively uncommon compared with those originating from the anterior cruciate ligament.1,2 Arthroscopic excision of cysts associated with the PCL that are located completely in the posterior compartment of the knee joint is often technically demanding. The purpose of this retrospective study was to evaluate a series of cases of PCL ganglia treated by arthroscopic excision through a posterior trans-septal portal. We discuss the clinical, magnetic resonance imaging (MRI), and arthroscopic features of ganglion cysts arising from the PCL. Our hypothesis was that this surgical technique would allow complete excision of the PCL ganglion, improving the clinical outcome.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 28, No 1 (January), 2012: pp 95-99
95
96
T-Y. TSAI ET AL. a single radiologist experienced in musculoskeletal imaging. The inclusion criteria were MRI diagnosis of symptomatic PCL cyst (pain or locking) with failed conservative medical treatment for 6 months, as well as receipt of arthroscopic examination and excision for this condition. The exclusion criteria were multiligament injuries, anterior cruciate ligament tear, meniscal cyst, meniscal horizontal tear requiring suture repair, loss to follow-up, and time after arthroscopic treatment of less than 1 year. Informed consent was obtained from all patients in the study. All the ganglion cysts were excised arthroscopically through the posterior trans-septal portal (Fig 2). All patients were followed up with MRI evaluation at a mean of 36 months after surgery, and those images were interpreted by the same radiologist. In addition, International Knee Documentation Committee (IKDC) scores3 and range of motion (ROM) were recorded preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes.
FIGURE 1. Preoperative sagittal T2-weighted magnetic resonance image showing multilobulated cystic mass (arrow) with high intensity arising from posterior aspect of PCL of left knee.
METHODS Over a 4-year period (October 2005 to August 2009), all arthroscopies (1,036 patients) performed by a single surgeon experienced in this procedure were prospectively recorded, and the findings were entered into a database. This database was reviewed for cases of PCL cysts, and each patient’s presentation, arthroscopic findings, and clinical course were evaluated. All cysts were diagnosed preoperatively by MRI (Fig 1), and those images were interpreted by
Surgical Technique Patients were placed in the supine position under general anesthesia with the affected knee flexed 90°. A tourniquet was applied in all cases to control bleeding. Routine arthroscopic examination of the knee joint was performed through standard anterolateral and anteromedial portals. To visualize and manage the posterior compartment of the knee joint, a posterior trans-septal portal was established as described by Ahn et al.4 The first step involved establishing a posteromedial portal, followed by a posterolateral portal. An aperture at the posterior septum was created by a rod placed through the posterolateral portal, and the
FIGURE 2. Surgical technique: (A) The posterior septum (PS) is located between the PCL (P) and posterior capsule (PC). A ganglion cyst (GC) with its main component behind the PCL is shown. (B) The posterior trans-septal portal was created by an aperture at the posterior septum (PS). The ganglion cysts could be completely excised arthroscopically through the posterior trans-septal portal. (A, anterior cruciate ligament; LM, lateral meniscus; MM, medial meniscus.)
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FIGURE 3. Intraoperative photographs showing (A) arthroscopic view from posteromedial portal. A huge, whitish encapsulated ganglion cyst (GC) with its main component behind the PCL was found in a left knee joint. (B) Arthroscopic view from anterolateral portal. After complete excision of the ganglion cyst by a motorized shaver in a piecemeal fashion through the posterior trans-septal portal, the posterior capsule (PC) and posterior compartment can be seen. (FC, femoral condyle; MM, medial meniscus; PS, posterior septum; PM, posteromedial portal; PL, posterolateral portal.)
arthroscope was inserted through the posteromedial portal to view the ganglion cyst behind the PCL (Fig 3A). Before using a shaver to excise the entire cyst, we used punch forceps to obtain a specimen for histologic examination. A motorized shaver was inserted through the posterior trans-septal portal to excise the ganglion cyst against the posterior septum and posterior capsule in a piecemeal fashion (Fig 3B). It is important to maintain knee flexion while shaving and avoid shaving fatty tissue behind the posterior capsule, at the dangerous area of the popliteal vessel and tibial nerve (Fig 2). The postoperative rehabilitation program included early active motion with partial
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
weight bearing with crutches for the first 2 weeks, followed by full weight bearing. RESULTS A total of 17 patients (1.6%) met the inclusion criteria for the study. One of these patients was excluded because of meniscal horizontal tears, and another was excluded because of loss to follow-up. Finally, 15 patients were included in the analysis for this study (Table 1). The cysts occurred predominantly in male patients (male-female ratio, 2:1), and the mean age was 32
TABLE 1.
Patient Descriptive Data
Gender
Age (yr)
Right/ Left
Symptoms
History of Trauma
Preop ROM
Preop IKDC
Cyst Size on MRI (cm)
Time Postop (mo)
Postop ROM
Postop IKDC
Recurrence of Cyst
M M F M F M F M M M F M F M M
45 54 24 17 19 25 35 40 50 35 26 23 24 29 34
R R L R R L R L L R R L R L R
Pain, effusion Pain, effusion Pain Pain, effusion Pain Pain Pain Pain Pain, effusion Pain, effusion Pain Pain Pain Locking Pain
Yes Yes No Yes No No Yes No Yes Yes No Yes No No No
5-110 20-100 0-110 0-115 0-120 0-110 0-105 5-105 10-105 5-115 0-110 0-115 0-110 0-105 5-110
45 38 51 47 55 61 54 62 43 45 67 51 56 58 55
2.0 ⫻ 1.5 ⫻ 1.0 2.2 ⫻ 1.4 ⫻ 1.0 1.5 ⫻ 1.2 ⫻ 1.0 1.3 ⫻ 1.0 ⫻ 1.0 0.8 ⫻ 0.8 ⫻ 0.5 1.4 ⫻ 1.1 ⫻ 1.0 1.5 ⫻ 1.2 ⫻ 1.0 1.3 ⫻ 1.2 ⫻ 1.0 2.0 ⫻ 1.8 ⫻ 1.5 1.6 ⫻ 1.3 ⫻ 1.3 1.0 ⫻ 0.6 ⫻ 0.6 1.5 ⫻ 1.0 ⫻ 1.0 1.6 ⫻ 1.2 ⫻ 1.2 1.3 ⫻ 1.2 ⫻ 1.0 1.8 ⫻ 1.5 ⫻ 1.2
62 54 52 50 46 45 43 39 35 23 21 20 20 19 17
5-125 15-115 0-135 0-130 0-140 0-135 0-125 5-125 8-110 3-125 0-140 0-130 0-125 0-140 3-125
86 70 98 90 99 98 96 98 72 88 99 94 90 99 88
No No No No No No No No No No No No No No No
98
T-Y. TSAI ET AL.
years (range, 17 to 54 years). The cysts were located more frequently on the right side (right-left ratio, 3:2). Of the 15 patients, 7 (47%) reported a history of antecedent trauma. The most common presenting complaint was pain with flexion (14 patients). Five patients had an effusion at presentation preoperatively (33%). All patients had reduced ROM (mean, 3° to 110°). The mean preoperative IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 (7%). The mean size of the cysts in our series was 1.5 ⫻ 1.2 ⫻ 1.0 cm measured on MRI. Histologic examination was performed in all cases and confirmed myxoid degeneration with ganglion formation. All patients were followed up with MRI evaluation, with a mean follow-up time of 36 months (range, 17 to 62 months). ROM was improved, with a mean of 3° to 128°, after arthroscopic excision of the cyst through the posterior trans-septal portal. The IKDC knee score was calculated (Table 1). The mean IKDC score was 91 (range, 70 to 99; SD, 9.3), with only 2 patients (cases 2 and 9) having a score of less than 75. Cysts did not recur in any of the 15 patients according to MRI evaluation.
DISCUSSION Ganglia are cystic lesions that contain a glassy, clear, and jelly-like fluid and can occur within muscle, menisci, and tendons.5 Intra-articular ganglion cysts of the knee are uncommon and mainly arise from the alar folds of the cruciate ligaments.6 The reported incidence is 1.3% among patients referred for MRI examinations of the knee7 and 0.6% among those undergoing arthroscopic examinations.8 This incidence of PCL cysts is comparable to that in our series (1.6%) based on our arthroscopic findings. Although they can occur at any age, cruciate ganglion cysts most often appear between 20 and 40 years of age, and they are more common in men.9 The patients in our study had a mean age of 32 years and were predominantly male patients. The pathogenesis of ganglion cysts is unclear. Theories include synovial tissue herniation, connective tissue degeneration after trauma, mucin deterioration of connective tissue, ectopia of synovial tissue, and proliferation of pluripotential mesenchymal stem cells.7,10-12 In our series 7 of 15 patients (47%) reported a history of antecedent trauma. Trauma appears to play a significant role in the pathogenesis of ganglion cysts.11,13,14
Ganglia associated with the PCL are usually well defined, lobulated, and multiloculated, occurring along the posterior surface of the ligament. A ganglion is smooth walled, translucent, and white and contains clear, highly viscous mucin consisting of hyaluronic acid, albumin, globulin, and glucosamine.15 In our series the location of the main cystic component was posterior to the PCL in 93% of cases and anterior to the PCL in 7% of cases. This finding is consistent with the report of DeFriend et al.6 The clinical manifestations of ganglion cysts associated with the PCL are variable and nonspecific and may include pain, limitation of ROM, and joint-line tenderness simulating other intra-articular pathology such as meniscal and chondral lesions.1 In our series pain was the most common clinical presentation (93%), and it was exacerbated with functional activities, such as running, stair climbing, or squatting. Orthopaedic examination of the knee shows a stable knee.11 Symptoms arising from a ganglion cyst may be associated with the location, size, and dimensions of the ganglion, which may change over time.5 In addition, changes in the shape and dimensions of the ganglion with knee motion stimulate nerve endings in the synovial membrane, causing knee pain.16 The clinical features of a ganglion cyst involving the PCL may mimic internal derangement of the knee and should be differentiated from meniscal tears, meniscal cysts, synovial proliferation disorders, synovial chondromatosis, synovial hemangioma, and synovial sarcoma.17 PCL ganglion cysts are typically diagnosed incidentally while one is ruling out serious pathology with diagnostic ultrasound and MRI. Plain radiography can be used to rule out intra-articular loose bodies.11 If these films are negative, an MRI evaluation may determine whether pathology exists. MRI is a good option for evaluating cystic masses because of its noninvasive nature. MRI can identify the size and location of the cystic mass with low T1-weighted signal intensity and high T2-weighted signal intensity.1 MRI evaluation can also detect additional intraarticular pathology. Because no specific physical examination technique can accurately diagnose ganglion cysts, MRI is a good method for diagnosing intraarticular ganglion cysts associated with cruciate ligaments. The main alternative treatment for symptomatic PCL ganglion cysts is surgery, and the most common approach is arthroscopic resection (which is associated with a lower rate of recurrence than other procedures).2,13,16 Arthroscopy permits complete examination of the knee joint and identification and treatment
EXCISION PCL CYSTS USING POSTERIOR TRANS-SEPTAL PORTAL of other identified pathology. However, arthroscopic excision of cystic lesions posterior to the PCL through the normal anterior portals is often technically demanding. In these cases the establishment of the posterior trans-septal portal is a good option. In our series all patients underwent complete excision of the entire PCL cyst arthroscopically through the posterior transseptal portal. This technique greatly improved the visualization of the posterosuperior aspect of the femoral condyles, the posterior portion of the PCL, the entire periphery of the posterior horn of the meniscus, the posterior meniscofemoral ligament, and the posterior aspect of the capsule.18 Postoperatively, most patients had excellent results, with a mean IKDC score of 91 (range, 70 to 99; SD, 9.3); 2 patients (cases 2 and 9) had scores below 75 because of the presence of advanced osteoarthritis. However, the knee function (IKDC) of these 2 patients still improved postoperatively (from 38 to 70 and from 43 to 72, respectively). In our 15 cases, no meniscal lesion or other intra-articular pathology had to be repaired during surgery. Therefore surgery involving excision of PCL cysts directly affects the clinical outcomes. At the mean follow-up time of 36 months, MRI examination showed no cyst recurrence in any of the patients. Similar findings have been noted by other researchers.9 Our study shows that using the posterior trans-septal portal is a good option for complete excision of lesions whose main cystic component is located posterior to the PCL. The limitations of our study include the small number of patients, the retrospective design, and the lack of a control group. However, unlike previously reported studies, our study established clinical outcomes of surgery. CONCLUSIONS Ganglion cysts associated with the PCL are uncommon but can lead to considerable pain. Patients may have a sensation of fullness during knee motion, limitation of knee ROM, and occasional swelling, effusion, and joint-line tenderness. Cystic lesions are mainly diagnosed incidentally, and MRI is a noninvasive option for evaluating cystic masses and additional intra-articular
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pathology. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence in patients with PCL ganglia. REFERENCES 1. Huang GS, Lee CH, Chan WP, et al. Ganglion cysts of the cruciate ligaments. Acta Radiol 2002;43:419-424. 2. Krudwig WK, Schulte KK, Heinemann C. Intra-articular ganglion cysts of the knee joint: A report of 85 cases and review of the literature. Knee Surg Sports Traumatol Arthrosc 2004; 12:123-129. 3. Irrgang JJ, Anderson AF, Boland AL, et al. Development and validation of the international knee documentation committee subjective knee form. Am J Sports Med 2001;29:600-613. 4. Ahn JH, Ha CW. Posterior trans-septal portal for arthroscopic surgery of the knee joint. Arthroscopy 2000;16:774-779. 5. Zantop T, Rusch A, Hassenpflug J, Petersen W. Intra-articular ganglion cysts of the cruciate ligaments: Case report and review of the literature. Arch Orthop Trauma Surg 2003;123: 195-198. 6. DeFriend DE, Schranz PJ, Silver DA. Ultrasound-guided aspiration of posterior cruciate ligament ganglion cysts. Skeletal Radiol 2001;30:411-414. 7. Bui-Mansfield LT, Youngberg RA. Intraarticular ganglia of the knee: Prevalence, presentation, etiology, and management. AJR Am J Roentgenol 1997;168:123-127. 8. Brown MF, Dandy DJ. Intra-articular ganglia in the knee. Arthroscopy 1990;6:322-323. 9. Shetty GM, Nha KW, Patil SP, et al. Ganglion cysts of the posterior cruciate ligament. Knee 2008;15:325-329. 10. Bellelli A, De Luca F, Maresca G, Nardis P. Synovial cyst of the cruciate ligament. Findings with magnetic resonance in 8 symptomatic cases. Radiol Med 1996;92:346-350 (in Italian). 11. Deutsch A, Veltri DM, Altchek DW, Potter HG, Warren RF, Wickiewicz TL. Symptomatic intraarticular ganglia of the cruciate ligaments of the knee. Arthroscopy 1994;10:219-223. 12. Durante JA. Ganglion cyst on the posterior cruciate ligament: A case report. J Can Chiropr Assoc 2009;53:334-338. 13. García-Alvarez F, García-Pequerul JM, Avila JL, Sainz JM, Castiella T. Ganglion cysts associated with cruciate ligaments of the knee: A possible cause of recurrent knee pain. Acta Orthop Belg 2000;66:490-494. 14. Sumen Y, Ochi M, Deie M, Adachi N, Ikuta Y. Ganglion cysts of the cruciate ligaments detected by MRI. Int Orthop 1999; 23:58-60. 15. Seki K, Mine T, Tanaka H, Isida Y, Taguchi T. Locked knee caused by intraarticular ganglion. Knee Surg Sports Traumatol Arthrosc 2006;14:859-861. 16. Kim RS, Kim KT, Lee JY, Lee KY. Ganglion cysts of the posterior cruciate ligament. Arthroscopy 2003;19:E36-E40. 17. Tyrrell PN, Cassar-Pullicino VN, McCall IW. Intra-articular ganglion cysts of the cruciate ligaments. Eur Radiol 2000;10: 1233-1238. 18. Ahn JH, Lee DH, Lee YS, Wang JH, Ha HC. Clearing a blind spot in knee arthroscopy: Popliteal bursa. Knee Surg Sports Traumatol Arthrosc 2008;16:549-552.
Purpose: To evaluate clinical outcomes of arthroscopic excision of ganglion cysts involving the posterior cruciate ligament (PCL) using the posterior trans-septal portal in the knee. Methods: A retrospective study was performed of 15 cases of ganglion cyst involving the PCL treated at our institution over a period of 4 years. All the cysts were diagnosed and had their location confirmed preoperatively by magnetic resonance imaging (MRI). All the cysts were excised arthroscopically through the posterior trans-septal portal. All patients were followed up with MRI evaluation at a mean of 36 months after surgery. In addition, International Knee Documentation Committee (IKDC) scores and range of motion (ROM) were obtained preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes. Results: Most of the patients were male patients, and the mean age was 32 years. The most common presenting complaint was pain and difficulty in knee flexion. Preoperatively, the mean ROM was 3° to 110° and the mean IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 patient (7%). After surgery, MRI evaluation at a mean follow-up time of 36 months showed no cyst recurrence. Postoperatively, the mean IKDC score was 91 (range, 70 to 99; SD, 9.3) and the mean ROM was 3° to 128°. Conclusions: Ganglion cysts associated with the PCL can cause knee pain and limitation of knee flexion. MRI evaluation is a noninvasive method of diagnosing PCL ganglion cysts. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence. Level of Evidence: Level IV, therapeutic case series.
G
anglion cysts are benign lesions arising from the joint capsule or tendon sheath and contain mucinous fluid. Intra-articular ganglia of the knee
From the Department of Orthopedics, Tri-Service General Hospital, National Defense Medical Center (T-Y.T., Y-S.Y., K-Y.L., C-W.L., H-C.S., L-C.L., R-Y.P.), Taipei; Department of Orthopedics, Hualien Armed Forces General Hospital (T-Y.T., F-J.T.), Hualien; and Department of Orthopedics, Taipei Medical University (C-H.L.), Taipei, Taiwan. The authors report no conflicts of interest. Received February 21, 2011; accepted July 19, 2011. Address correspondence to Ru-Yu Pan, M.D., Ph.D., Department of Orthopedics, Tri-Service General Hospital, National Defense Medical Center 325, Cheng-Kung Road Section 2, Taipei 114, Taiwan. E-mail: [email protected] Crown Copyright © 2012 Published by Elsevier Inc. on behalf of the Arthroscopy Association of North America. All rights reserved. 0749-8063/11117/$36.00 doi:10.1016/j.arthro.2011.07.013
are unusual lesions and may produce clinical manifestations such as knee pain and limitation of knee flexion mimicking internal derangement. Ganglion cysts originating from the posterior cruciate ligament (PCL) are relatively uncommon compared with those originating from the anterior cruciate ligament.1,2 Arthroscopic excision of cysts associated with the PCL that are located completely in the posterior compartment of the knee joint is often technically demanding. The purpose of this retrospective study was to evaluate a series of cases of PCL ganglia treated by arthroscopic excision through a posterior trans-septal portal. We discuss the clinical, magnetic resonance imaging (MRI), and arthroscopic features of ganglion cysts arising from the PCL. Our hypothesis was that this surgical technique would allow complete excision of the PCL ganglion, improving the clinical outcome.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 28, No 1 (January), 2012: pp 95-99
95
96
T-Y. TSAI ET AL. a single radiologist experienced in musculoskeletal imaging. The inclusion criteria were MRI diagnosis of symptomatic PCL cyst (pain or locking) with failed conservative medical treatment for 6 months, as well as receipt of arthroscopic examination and excision for this condition. The exclusion criteria were multiligament injuries, anterior cruciate ligament tear, meniscal cyst, meniscal horizontal tear requiring suture repair, loss to follow-up, and time after arthroscopic treatment of less than 1 year. Informed consent was obtained from all patients in the study. All the ganglion cysts were excised arthroscopically through the posterior trans-septal portal (Fig 2). All patients were followed up with MRI evaluation at a mean of 36 months after surgery, and those images were interpreted by the same radiologist. In addition, International Knee Documentation Committee (IKDC) scores3 and range of motion (ROM) were recorded preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes.
FIGURE 1. Preoperative sagittal T2-weighted magnetic resonance image showing multilobulated cystic mass (arrow) with high intensity arising from posterior aspect of PCL of left knee.
METHODS Over a 4-year period (October 2005 to August 2009), all arthroscopies (1,036 patients) performed by a single surgeon experienced in this procedure were prospectively recorded, and the findings were entered into a database. This database was reviewed for cases of PCL cysts, and each patient’s presentation, arthroscopic findings, and clinical course were evaluated. All cysts were diagnosed preoperatively by MRI (Fig 1), and those images were interpreted by
Surgical Technique Patients were placed in the supine position under general anesthesia with the affected knee flexed 90°. A tourniquet was applied in all cases to control bleeding. Routine arthroscopic examination of the knee joint was performed through standard anterolateral and anteromedial portals. To visualize and manage the posterior compartment of the knee joint, a posterior trans-septal portal was established as described by Ahn et al.4 The first step involved establishing a posteromedial portal, followed by a posterolateral portal. An aperture at the posterior septum was created by a rod placed through the posterolateral portal, and the
FIGURE 2. Surgical technique: (A) The posterior septum (PS) is located between the PCL (P) and posterior capsule (PC). A ganglion cyst (GC) with its main component behind the PCL is shown. (B) The posterior trans-septal portal was created by an aperture at the posterior septum (PS). The ganglion cysts could be completely excised arthroscopically through the posterior trans-septal portal. (A, anterior cruciate ligament; LM, lateral meniscus; MM, medial meniscus.)
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FIGURE 3. Intraoperative photographs showing (A) arthroscopic view from posteromedial portal. A huge, whitish encapsulated ganglion cyst (GC) with its main component behind the PCL was found in a left knee joint. (B) Arthroscopic view from anterolateral portal. After complete excision of the ganglion cyst by a motorized shaver in a piecemeal fashion through the posterior trans-septal portal, the posterior capsule (PC) and posterior compartment can be seen. (FC, femoral condyle; MM, medial meniscus; PS, posterior septum; PM, posteromedial portal; PL, posterolateral portal.)
arthroscope was inserted through the posteromedial portal to view the ganglion cyst behind the PCL (Fig 3A). Before using a shaver to excise the entire cyst, we used punch forceps to obtain a specimen for histologic examination. A motorized shaver was inserted through the posterior trans-septal portal to excise the ganglion cyst against the posterior septum and posterior capsule in a piecemeal fashion (Fig 3B). It is important to maintain knee flexion while shaving and avoid shaving fatty tissue behind the posterior capsule, at the dangerous area of the popliteal vessel and tibial nerve (Fig 2). The postoperative rehabilitation program included early active motion with partial
Case 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
weight bearing with crutches for the first 2 weeks, followed by full weight bearing. RESULTS A total of 17 patients (1.6%) met the inclusion criteria for the study. One of these patients was excluded because of meniscal horizontal tears, and another was excluded because of loss to follow-up. Finally, 15 patients were included in the analysis for this study (Table 1). The cysts occurred predominantly in male patients (male-female ratio, 2:1), and the mean age was 32
TABLE 1.
Patient Descriptive Data
Gender
Age (yr)
Right/ Left
Symptoms
History of Trauma
Preop ROM
Preop IKDC
Cyst Size on MRI (cm)
Time Postop (mo)
Postop ROM
Postop IKDC
Recurrence of Cyst
M M F M F M F M M M F M F M M
45 54 24 17 19 25 35 40 50 35 26 23 24 29 34
R R L R R L R L L R R L R L R
Pain, effusion Pain, effusion Pain Pain, effusion Pain Pain Pain Pain Pain, effusion Pain, effusion Pain Pain Pain Locking Pain
Yes Yes No Yes No No Yes No Yes Yes No Yes No No No
5-110 20-100 0-110 0-115 0-120 0-110 0-105 5-105 10-105 5-115 0-110 0-115 0-110 0-105 5-110
45 38 51 47 55 61 54 62 43 45 67 51 56 58 55
2.0 ⫻ 1.5 ⫻ 1.0 2.2 ⫻ 1.4 ⫻ 1.0 1.5 ⫻ 1.2 ⫻ 1.0 1.3 ⫻ 1.0 ⫻ 1.0 0.8 ⫻ 0.8 ⫻ 0.5 1.4 ⫻ 1.1 ⫻ 1.0 1.5 ⫻ 1.2 ⫻ 1.0 1.3 ⫻ 1.2 ⫻ 1.0 2.0 ⫻ 1.8 ⫻ 1.5 1.6 ⫻ 1.3 ⫻ 1.3 1.0 ⫻ 0.6 ⫻ 0.6 1.5 ⫻ 1.0 ⫻ 1.0 1.6 ⫻ 1.2 ⫻ 1.2 1.3 ⫻ 1.2 ⫻ 1.0 1.8 ⫻ 1.5 ⫻ 1.2
62 54 52 50 46 45 43 39 35 23 21 20 20 19 17
5-125 15-115 0-135 0-130 0-140 0-135 0-125 5-125 8-110 3-125 0-140 0-130 0-125 0-140 3-125
86 70 98 90 99 98 96 98 72 88 99 94 90 99 88
No No No No No No No No No No No No No No No
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T-Y. TSAI ET AL.
years (range, 17 to 54 years). The cysts were located more frequently on the right side (right-left ratio, 3:2). Of the 15 patients, 7 (47%) reported a history of antecedent trauma. The most common presenting complaint was pain with flexion (14 patients). Five patients had an effusion at presentation preoperatively (33%). All patients had reduced ROM (mean, 3° to 110°). The mean preoperative IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 (7%). The mean size of the cysts in our series was 1.5 ⫻ 1.2 ⫻ 1.0 cm measured on MRI. Histologic examination was performed in all cases and confirmed myxoid degeneration with ganglion formation. All patients were followed up with MRI evaluation, with a mean follow-up time of 36 months (range, 17 to 62 months). ROM was improved, with a mean of 3° to 128°, after arthroscopic excision of the cyst through the posterior trans-septal portal. The IKDC knee score was calculated (Table 1). The mean IKDC score was 91 (range, 70 to 99; SD, 9.3), with only 2 patients (cases 2 and 9) having a score of less than 75. Cysts did not recur in any of the 15 patients according to MRI evaluation.
DISCUSSION Ganglia are cystic lesions that contain a glassy, clear, and jelly-like fluid and can occur within muscle, menisci, and tendons.5 Intra-articular ganglion cysts of the knee are uncommon and mainly arise from the alar folds of the cruciate ligaments.6 The reported incidence is 1.3% among patients referred for MRI examinations of the knee7 and 0.6% among those undergoing arthroscopic examinations.8 This incidence of PCL cysts is comparable to that in our series (1.6%) based on our arthroscopic findings. Although they can occur at any age, cruciate ganglion cysts most often appear between 20 and 40 years of age, and they are more common in men.9 The patients in our study had a mean age of 32 years and were predominantly male patients. The pathogenesis of ganglion cysts is unclear. Theories include synovial tissue herniation, connective tissue degeneration after trauma, mucin deterioration of connective tissue, ectopia of synovial tissue, and proliferation of pluripotential mesenchymal stem cells.7,10-12 In our series 7 of 15 patients (47%) reported a history of antecedent trauma. Trauma appears to play a significant role in the pathogenesis of ganglion cysts.11,13,14
Ganglia associated with the PCL are usually well defined, lobulated, and multiloculated, occurring along the posterior surface of the ligament. A ganglion is smooth walled, translucent, and white and contains clear, highly viscous mucin consisting of hyaluronic acid, albumin, globulin, and glucosamine.15 In our series the location of the main cystic component was posterior to the PCL in 93% of cases and anterior to the PCL in 7% of cases. This finding is consistent with the report of DeFriend et al.6 The clinical manifestations of ganglion cysts associated with the PCL are variable and nonspecific and may include pain, limitation of ROM, and joint-line tenderness simulating other intra-articular pathology such as meniscal and chondral lesions.1 In our series pain was the most common clinical presentation (93%), and it was exacerbated with functional activities, such as running, stair climbing, or squatting. Orthopaedic examination of the knee shows a stable knee.11 Symptoms arising from a ganglion cyst may be associated with the location, size, and dimensions of the ganglion, which may change over time.5 In addition, changes in the shape and dimensions of the ganglion with knee motion stimulate nerve endings in the synovial membrane, causing knee pain.16 The clinical features of a ganglion cyst involving the PCL may mimic internal derangement of the knee and should be differentiated from meniscal tears, meniscal cysts, synovial proliferation disorders, synovial chondromatosis, synovial hemangioma, and synovial sarcoma.17 PCL ganglion cysts are typically diagnosed incidentally while one is ruling out serious pathology with diagnostic ultrasound and MRI. Plain radiography can be used to rule out intra-articular loose bodies.11 If these films are negative, an MRI evaluation may determine whether pathology exists. MRI is a good option for evaluating cystic masses because of its noninvasive nature. MRI can identify the size and location of the cystic mass with low T1-weighted signal intensity and high T2-weighted signal intensity.1 MRI evaluation can also detect additional intraarticular pathology. Because no specific physical examination technique can accurately diagnose ganglion cysts, MRI is a good method for diagnosing intraarticular ganglion cysts associated with cruciate ligaments. The main alternative treatment for symptomatic PCL ganglion cysts is surgery, and the most common approach is arthroscopic resection (which is associated with a lower rate of recurrence than other procedures).2,13,16 Arthroscopy permits complete examination of the knee joint and identification and treatment
EXCISION PCL CYSTS USING POSTERIOR TRANS-SEPTAL PORTAL of other identified pathology. However, arthroscopic excision of cystic lesions posterior to the PCL through the normal anterior portals is often technically demanding. In these cases the establishment of the posterior trans-septal portal is a good option. In our series all patients underwent complete excision of the entire PCL cyst arthroscopically through the posterior transseptal portal. This technique greatly improved the visualization of the posterosuperior aspect of the femoral condyles, the posterior portion of the PCL, the entire periphery of the posterior horn of the meniscus, the posterior meniscofemoral ligament, and the posterior aspect of the capsule.18 Postoperatively, most patients had excellent results, with a mean IKDC score of 91 (range, 70 to 99; SD, 9.3); 2 patients (cases 2 and 9) had scores below 75 because of the presence of advanced osteoarthritis. However, the knee function (IKDC) of these 2 patients still improved postoperatively (from 38 to 70 and from 43 to 72, respectively). In our 15 cases, no meniscal lesion or other intra-articular pathology had to be repaired during surgery. Therefore surgery involving excision of PCL cysts directly affects the clinical outcomes. At the mean follow-up time of 36 months, MRI examination showed no cyst recurrence in any of the patients. Similar findings have been noted by other researchers.9 Our study shows that using the posterior trans-septal portal is a good option for complete excision of lesions whose main cystic component is located posterior to the PCL. The limitations of our study include the small number of patients, the retrospective design, and the lack of a control group. However, unlike previously reported studies, our study established clinical outcomes of surgery. CONCLUSIONS Ganglion cysts associated with the PCL are uncommon but can lead to considerable pain. Patients may have a sensation of fullness during knee motion, limitation of knee ROM, and occasional swelling, effusion, and joint-line tenderness. Cystic lesions are mainly diagnosed incidentally, and MRI is a noninvasive option for evaluating cystic masses and additional intra-articular
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pathology. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence in patients with PCL ganglia. REFERENCES 1. Huang GS, Lee CH, Chan WP, et al. Ganglion cysts of the cruciate ligaments. Acta Radiol 2002;43:419-424. 2. Krudwig WK, Schulte KK, Heinemann C. Intra-articular ganglion cysts of the knee joint: A report of 85 cases and review of the literature. Knee Surg Sports Traumatol Arthrosc 2004; 12:123-129. 3. Irrgang JJ, Anderson AF, Boland AL, et al. Development and validation of the international knee documentation committee subjective knee form. Am J Sports Med 2001;29:600-613. 4. Ahn JH, Ha CW. Posterior trans-septal portal for arthroscopic surgery of the knee joint. Arthroscopy 2000;16:774-779. 5. Zantop T, Rusch A, Hassenpflug J, Petersen W. Intra-articular ganglion cysts of the cruciate ligaments: Case report and review of the literature. Arch Orthop Trauma Surg 2003;123: 195-198. 6. DeFriend DE, Schranz PJ, Silver DA. Ultrasound-guided aspiration of posterior cruciate ligament ganglion cysts. Skeletal Radiol 2001;30:411-414. 7. Bui-Mansfield LT, Youngberg RA. Intraarticular ganglia of the knee: Prevalence, presentation, etiology, and management. AJR Am J Roentgenol 1997;168:123-127. 8. Brown MF, Dandy DJ. Intra-articular ganglia in the knee. Arthroscopy 1990;6:322-323. 9. Shetty GM, Nha KW, Patil SP, et al. Ganglion cysts of the posterior cruciate ligament. Knee 2008;15:325-329. 10. Bellelli A, De Luca F, Maresca G, Nardis P. Synovial cyst of the cruciate ligament. Findings with magnetic resonance in 8 symptomatic cases. Radiol Med 1996;92:346-350 (in Italian). 11. Deutsch A, Veltri DM, Altchek DW, Potter HG, Warren RF, Wickiewicz TL. Symptomatic intraarticular ganglia of the cruciate ligaments of the knee. Arthroscopy 1994;10:219-223. 12. Durante JA. Ganglion cyst on the posterior cruciate ligament: A case report. J Can Chiropr Assoc 2009;53:334-338. 13. García-Alvarez F, García-Pequerul JM, Avila JL, Sainz JM, Castiella T. Ganglion cysts associated with cruciate ligaments of the knee: A possible cause of recurrent knee pain. Acta Orthop Belg 2000;66:490-494. 14. Sumen Y, Ochi M, Deie M, Adachi N, Ikuta Y. Ganglion cysts of the cruciate ligaments detected by MRI. Int Orthop 1999; 23:58-60. 15. Seki K, Mine T, Tanaka H, Isida Y, Taguchi T. Locked knee caused by intraarticular ganglion. Knee Surg Sports Traumatol Arthrosc 2006;14:859-861. 16. Kim RS, Kim KT, Lee JY, Lee KY. Ganglion cysts of the posterior cruciate ligament. Arthroscopy 2003;19:E36-E40. 17. Tyrrell PN, Cassar-Pullicino VN, McCall IW. Intra-articular ganglion cysts of the cruciate ligaments. Eur Radiol 2000;10: 1233-1238. 18. Ahn JH, Lee DH, Lee YS, Wang JH, Ha HC. Clearing a blind spot in knee arthroscopy: Popliteal bursa. Knee Surg Sports Traumatol Arthrosc 2008;16:549-552.