Lateral meniscal cysts: long-term clinical and radiological results of a partial meniscectomy and percutaneous decompressive needling

Long-term clinical and radiological outcomes after arthroscopic partial meniscectomy on stable knees are better for traumatic tears when compared to degenerative lesions: A systematic review

PURPOSE

An arthroscopic partial meniscectomy (APM) for degenerative meniscus lesions and traumatic meniscus tears are two distinct entities and their long-term outcomes are rarely reported. The aim of this review was to compare the long-term (clinical and radiological) results of APM performed on stable knees for traumatic tears (TT) or degenerative lesions (DL).

METHODS

Pubmed, Scopus and Embase databases were searched to identify relevant studies published between 2010 and 2023 using the keywords 'meniscectomy' OR 'meniscectomies' OR 'meniscal resection'. English-language, Levels I-IV evidence studies reporting either radiographic or clinical outcome measures with a minimum of 6 years' follow-up after APM were included. Studies including discoid meniscus, open meniscectomy, unstable knee and combination with other procedures were excluded. To rate the quality of evidence, the methodological index for non-randomized studies was used.

RESULTS

Thirty-two studies were included, with follow-up periods ranging from 6 to 22 years. Eleven studies dealt with TT with a mean age of 31.5 ± 6.6 years and a mean follow-up of 11.6 ± 6.9 years. At the last follow-up, radiographic osteoarthritis (OA) ranged from 36% to 76%, with an average rate of 48 ± 19%; functional scores ranged from 71 to 97, with a mean of 90 ± 4 for the Lysholm score, 86 ± 10 for the International Knee Documentation Committee (IKDC) and 94 ± 16 for the knee injury and osteoarthritis outcome (KOOS). Twenty-one studies dealt with DL with a mean age of 49.9 ± 7.2 years and a mean follow-up of 14.9 ± 6.3 years. At the last follow-up, radiographic OA ranged from 23% to 97%, with an average rate of 77 ± 28%; functional scores ranged from 40 to 87, with a mean of 79 ± 10 for the Lysholm score and 71 ± 16 for the IKDC.

CONCLUSION

Ten-year clinical outcomes of APM are better for TTs when compared to DLs. Rates of OA are difficult to compare but lower for TTs.

LEVEL OF EVIDENCE

Level IV.

Arthroscopic evaluation of anatomical variations of the oblique popliteal ligament and their association with popliteal cyst formation

INTRODUCTION

The posteromedial compartment of the knee houses several important anatomical structures, including the oblique popliteal ligament (OPL), an accessory insertion tendon of the semimembranosus muscle. Popliteal cysts develop from the synovial bursa located between the medial gastrocnemius and the semimembranosus, typically secondary to intra-articular pathologies causing effusion. This study aimed to describe the normal anatomy of the postero-medial capsule of the knee and its anatomical variations, particularly in the presence of popliteal cysts.

MATERIALS AND METHODS

This was a prospective descriptive study conducted over four consecutive months, including 96 knees from 96 patients who underwent arthroscopy for various intra-articular pathologies. The anatomy of the oblique popliteal ligament was categorized into four types: integrated OPL (Type 1), prominent "cord-like" OPL (Type 2A), normally prominent OPL (Type 2B), and bulging OPL (Type 3). The presence of popliteal cysts was evaluated preoperatively using magnetic resonance imaging (MRI).

RESULTS

Type 1 OPL was observed in 13 knees (13.5%), Type 2A in 22 (22.9%), Type 2B in 40 (41.7%), and Type 3 in 21 (21.9%). MRI revealed popliteal cysts in 20 knees (20.8%), of which 8 (8.3%) were symptomatic. No popliteal cysts were identified in Type 1 knees. Cysts were present in 2 of 22 Type 2A knees (9.1%), 6 of 40 Type 2B knees (15%), and 12 of 21 Type 3 knees (57.1%). A statistically significant relationship was found between the anatomical type of the postero-medial capsule and the presence of a popliteal cyst (p < 0.001).

CONCLUSION

Arthroscopic anatomy of the postero-medial capsule appears altered in the presence of a popliteal cyst. This alteration is characterized by a bulging OPL within the joint, creating a communication orifice at its superior margin leading to the cyst. Posteromedial synovectomies aimed at disrupting the unidirectional flow mechanism into the cyst should target a triangular area defined by the medial gastrocnemius, the semimembranosus, and the oblique popliteal ligament.

LEVEL OF EVIDENCE

IV; observational study.

The incidence of meniscal cyst formation following meniscal repair using the all-inside suture anchor device is comparable to conventional techniques

Purpose

Post-operative meniscal cyst formation occurs following all-inside device meniscal repair. This study aimed to compare the incidence of cysts in patients who underwent meniscal repair with and without all-inside suture devices.

Methods

This retrospective study included 227 knees that underwent meniscal repair between 2021 and 2022. The incidence of post-operative meniscal cysts was compared between patients who underwent repair using an all-inside suture anchor device (Group SA) and those who did not use an anchor (Group NA), based on post-operative magnetic resonance imaging (MRI) findings. Risk factors, such as the number of anchors used, were investigated. Using a subgroup analysis, the incidence of meniscal cysts based on the type of device used was investigated.

Results

Groups SA and NA comprised 125 and 102 knees, respectively. Group SA had 11 cases of cysts (9% incidence), whereas Group NA had 7 cases (7% incidence), and no statistically significant difference was observed (p = 0.63). Symptomatic cysts were observed in two patients (1.6%) in Group SA, whereas none was observed in Group NA (0%); the difference was not significant (p = 0.50). Factors such as the number of anchors and sutures used and MRI timing were not identified as risk factors. Cyst incidence varied according to anchor type: Stryker AIR+ (4 out of 55, 7%), Smith & Nephew Fast-Fix 360 (7 out of 56, 13%) and Arthrex Fiber Stitch (0 out of 26, 0%), with no significant difference found (p = 0.14).

Conclusion

The incidence of cysts in patients undergoing meniscal repair with an all-inside suture anchor device was 9%, showing no significant difference compared with Group NA. Cyst incidence was not affected by device type.

Level of Evidence

Level III, retrospective comparative study.

Double posteromedial portals versus single posteromedial portal for arthroscopic management of popliteal cysts

BACKGROUND

As a common disease in orthopedic clinics, popliteal cysts often coexist with intra-articular lesions. Compared with traditional open surgery, arthroscopic treatment of popliteal cysts is less traumatic, and intra-articular lesions can be treated. The 'one-way valve' mechanism of the popliteal cyst can be removed by expanding the communication between the articular cavity and the cyst to avoid cyst recurrence. In terms of arthroscopic techniques, the comparison of clinical effects between the double posteromedial portal (DPP) and single posteromedial portal (SPP) has rarely been studied. The purpose of this retrospective study was to compare the clinical effects of DPP and SPP.

METHODS

A total of 46 consecutive patients with symptomatic popliteal cysts who underwent arthroscopic treatment were included in this study and followed for approximately 1 year. All patients were divided into two groups according to the arthroscopic portals (DPP group and SPP group). The cyst size, Lysholm score and Rauschening-Lindgren (R-L) grade were evaluated before the operation for all patients, and the intra-articular lesions, operative time and complications were recorded after operation. At the last follow-up, the Lysholm score and R-L grade were recorded, and magnetic resonance imaging was used to evaluate the outcome of the cyst. The clinical data of the two groups was statistically compared and analyzed.

RESULTS

There were no significant differences in preoperative cyst size, Lysholm score or R-L grade between the two groups (P > 0.05). The operation time of the DPP group (67.52 ± 18.23 min) was longer than that of the SPP group (55.95 ± 16.40 min) (P = 0.030), but the recurrence rate of cysts in the DPP group (0%) was obviously lower than that in the SPP group (19.0%) (P = 0.046). There were no significant differences in the Lysholm score, R-L grade or complication rate between the two groups at the last follow-up (P > 0.05).

CONCLUSION

Arthroscopic treatment of popliteal cysts using double posteromedial portals was a safe and effective surgical method.

TRIAL REGISTRATION

ChiCTR, ChiCTR2200060115. Registered 19 May 2022, https://www.chictr.org.cn/showproj.html?proj=133199.

Arthroscopic Management of Meniscal Cysts: A Systematic Review

Purpose

The purpose of this study was to systematically review the outcomes of arthroscopic management of meniscal cysts and to compare the results across the reported surgical techniques.

Methods

Following the PRISMA methodology, 3 databases (PubMed, Scopus and Web of Science) were searched from inception to June 2021 for randomized controlled trials (RCTs) and observational studies reporting outcomes on patients with meniscal cysts who underwent arthroscopic surgery. The Mixed Methods Appraisal Tool (MMAT) was used to evaluate the study quality.

Results

Eighteen studies examining 753 patients (761 meniscal cysts; 92.5% in the lateral meniscus) were included. Overall, 486/736 (66.0%) patients underwent purely arthroscopic decompression, 174/736 (23.6%) received arthroscopic excision, 58/736 (7.9%) received arthroscopy assisted percutaneous drainage, and 18/736 (2.4%) received a combined procedure. The recurrence rate for meniscal cysts was 7.1% across all arthroscopic procedures; 8.3%, 3.4%, and 0% for arthroscopic decompression, arthroscopic excision, and arthroscopy assisted percutaneous drainage, respectively. A total of 79.3% of patients returned to the same level of sport and 85.7% had resolution or minimal knee symptoms after arthroscopic surgery for meniscal cysts. Patient perception of surgical outcomes after any type of arthroscopic surgery for meniscal cysts was reported by 5 studies, with 189/203 (93.1%) reporting satisfaction with their surgical procedure.

Conclusion

Based on current evidence, arthroscopic management of meniscal cysts yields satisfactory patient outcomes, low cyst recurrence rates and high return to sport rates regardless of the surgical technique. Rates of cyst recurrence were relatively higher with arthroscopic decompression versus excision and percutaneous drainage; however, prospective studies using modern surgical techniques are necessary to better evaluate the surgical outcomes and to compare those with nonoperative modalities, given that a significant proportion of the included articles in this review were relatively outdated.

Level of Evidence

Systematic review of level II and IV studies.

How to Perform a Giant Parameniscal Cyst Exeresis: Step by Step Technique

Parameniscal cysts are usually small cystic lesions, less than 2 cm in size, found along the meniscal periphery. They are rarely associated with extra-articular palpable mass. Magnetic resonance imaging is the diagnostic method of choice; giant meniscal cysts (>5 cm at its greatest diameter) are very rare, with few cases described in the literature. We describe a step-by-step open exeresis and arthroscopic meniscal suture technique for the treatment of a 9-cm giant parameniscal cyst located on the lateral side of the knee. Treatment of giant meniscal lesions requires caution during dissection and exeresis. Because acute meniscal lesions benefit from meniscal suture rather than meniscectomy, horizontal degenerative lesions may also present excellent results with repair techniques. We conclude that the combination of the open excision of the giant cyst with careful dissection and protection of neurovascular structures, combined with the arthroscopic meniscal suture, is a good strategy to approach such lesions.