Two-stage operation for treatment of a large dissecting popliteal cyst after failed total knee arthroplasty

Ruptured Popliteal Cysts Mimicking Deep Vein Thrombosis in Well-Functioning Total Knee Replacements: Report of Two Cases and Review of Literature

Background

Implant wear and loosening with eluding metal/polythene debris are commonly implicated in the occurrence of Baker’s cysts in post-operative total knee replacement (TKR) patients, who present with post-operative pain and swelling, mimicking deep venous thrombosis. However, we present two symptomatic cases presenting with ruptured Baker’s cysts post-TKRs, with no evidence of implant loosening or wear.

Cases Report

The 1st patient was a 55-year-old male, who underwent TKR for Grade 4 bilateral knee osteoarthritis and presented with acute onset of pain and swelling over the left popliteal fossa, which progressed to involve the calf. Radiographs showed no sign of infection or loosening, and venous color Doppler and magnetic resonance imaging (MRI) showed a hy-poechoic collection in the intermuscular plane at the upper part of popliteal fossa. Histological examination of the aspirated fluid showed mixed features of cystic fluid and a resolving hematoma. There was complete resolution of the 4 months with rest and graduated physiotherapy.

The 2nd patient was a 51-year-old female who developed the cystic swelling 2 years after the surgery, and the ultrasound showed hypoechoic echoes in a Baker’s cyst-like collection. Cytological findings were suggestive of hemorrhagic nature of the aspirate, without any evi-dence of polyethylene debris, and the cultures were sterile. She became asymptomatic over 4 weeks with conservative management; the swelling resolved after 3 months.

Conclusion

Majority of the cases in literature show implant loosening as cause of popliteal cysts after TKRs, however present cases highlight alternative mechanisms, and there are good chances of self-resolution of cysts with conservative treatment in such cases.

Arthroscopy-Assisted Treatment of Wear Debris Pseudotumor After Total Knee Arthroplasty: A Case Report

Background

Wear debris pseudotumors are a rare complication after total knee arthroplasty (TKA) and have seldom been reported in the recent literature. There is no consensus on the best therapeutic method, but the high quality curative treatment, safe, low invasive treatments are required for the patients.

Case presentation

In this paper, we present the case of a 74‐year‐old man with a wear debris pseudotumor after TKA with symptoms of severe pain and functional disability of his right knee. X‐ray examination showed that the medial compartment of the right knee was narrowing. Magnetic resonance imaging (MRI) and Doppler ultrasound both revealed a polycystic mass at the posteromedial side of the patient's right knee. Considering the bad health condition and the minimally invasive surgery requirement of this senior patient, arthroscopic knee debridement and percutaneous cystic mass suction were carried out simultaneously. Video arthroscopy of the right knee showed visible inflammatory soft tissue, obvious polyethylene fragments, wear of the polyethylene prothesis, and a broken polyethylene insert. The intraarticular polyethylene wear debris was removed as much as possible, and inflammatory soft tissue was debrided and sent for pathology. Postoperative pathology showed polyethylene debris in the soft tissue with an apparent multinucleated giant cell response, which was consistent with foreign body granuloma. All clinical manifestation was improved and Lysholm scores were significantly better at one year with this treatment, increasing from 32 points to 71 points.

Conclusion

After two years of follow‐up, the patient's knee joint was significantly relieved from soreness and pain, and walking was not significantly restricted. Our treatment could not address the root cause of the wear debris pseudotumor, which was due to prosthesis failure, but sometimes, such an approach is the safest, most economical, and most effective choice for patients who are intolerant to reoperation.

Metal wear-induced pseudotumour following an endoprosthetic knee replacement for Ewing sarcoma

Pseudotumours are well recognised as a complication of metal-on-metal hip arthroplasties and are thought to develop on the basis of an innate and adaptive immune response to cobalt-chrome (Co-Cr) wear particles. We report a case of a large pseudotumour that developed following a knee endoprosthetic replacement (EPR) undertaken for Ewing sarcoma. The lesion contained necrotic and degenerate connective tissue in which there were numerous scattered metal wear-containing macrophages, eosinophil polymorphs, lymphocytes, plasma cells and aseptic lymphocyte-dominated vascular-associated lesion-like lymphoid aggregates. Metal ion levels were elevated. No evidence of infection or tumour was noted and it was concluded that the lesion was most likely an inflammatory pseudotumour developing on the basis of an innate and adaptive immune response to components of Co-Cr metal wear derived from the knee EPR.

Intramuscular dissection of a large ganglion cyst into the gastrocnemius muscle

Ganglion cysts are lesions resulting from the myxoid degeneration of the connective tissue associated with joint capsules and tendon sheaths. Most common around the wrist joint, ganglion cysts may be found elsewhere in the body, including in and around the knee joint. Uncommonly, ganglion cysts can present intramuscularly. Previous reports document the existence of intramuscular ganglia, often without histologic confirmation. This article describes a case of an intramuscular ganglion cyst in the medial gastrocnemius muscle of a 53-year-old woman. The patient initially presented for discomfort associated with the lesion. Examination was consistent with intramuscular cystic lesion of unknown etiology. Ultrasound and magnetic resonance imaging revealed the origin of the mass at the semimembranosus-gastrocnemius bursa. Because of its location, the mass was initially suspected to be a dissecting Baker's cyst, an uncommon but previously reported diagnosis. The patient underwent surgical excision, and examination of the intact specimen revealed a thin, fibrous, walled cyst with no lining epithelium, which was consistent with a ganglion cyst. To the authors' knowledge, this is the first report in the orthopedic literature of a ganglion cyst dissecting into the gastrocnemius muscle. Because ganglion cysts commonly require excision for definitive treatment and do not respond well to treatment measures implemented for Baker's cysts, including resection of underlying meniscal tears, the authors believe it is important for orthopedic surgeons to be able to distinguish between Baker's and other cysts associated with the knee joint, including ganglion cysts, which may require more definitive treatment.

Multilobulated popliteal cyst after a failed total knee arthroplasty

Popliteal cyst is a rare finding after total knee arthroplasty (TKA), but when present, it might indicate a malfunction of the TKA related to generation of wear-particles, or loosening. We present a case of a multilobulated popliteal cyst developing in a patient 8 years after primary TKA. The cyst was associated with a mechanical prosthetic loosening. The primary complaint of the patient was pain in the posterior region of the knee. A two-stage procedure consisting of cyst excision at first, followed after 5 months by a revision TKA was performed. Intraoperatively, a darkish, multilobulated cyst with a well-defined thick wall filled with fluid containing polyethylene debris, communicating with the knee joint was found. After 3 years of follow-up, the patient was satisfied and walked without the support of a cane. The patient presented a satisfactory knee range of motion. Clinical, radiological and ultrasound investigations ruled out popliteal cyst recurrence. A dissecting popliteal cyst associated with a failed TKA should be excised because it contains polyethylene debris that constitutes an induced factor for prosthetic loosening. A two-stage procedure with quite a long time in-between, as presented in this paper, can be a useful alternative to manage such a problem, in particular in very old patients associated with other medical problems.

A large metallic cyst caused by wear particles after total knee arthroplasty

INTRODUCTION

A symptomatic cyst is an uncommon complication after total knee arthroplasty (TKA). We present a case of a 77-year-old woman with a large cyst in the right knee caused by metal wear debris from the failure of a Miller-Galante I TKA performed 13 years earlier.

CASE PRESENTATION

The patient was treated with a two-stage operation including revision of the TKA followed by excision of the cyst, because there was a direct communication between the joint cavity and the cyst, and because the patient reported pain corresponding to the cystic area after revision. The patient was pain-free and had a satisfactory result 17 months after the second operation, without recurrence of cyst formation.

CONCLUSION

We recommend two-stage surgery in which the first-stage is correction of the intra-articular pathology with revision TKA and the second-stage is excision of the cyst.

New insights into the development of popliteal cysts

Background

This prospective study was designed to investigate the aetiology of popliteal (Baker's) cysts.

Methods

Some 426 legs in 312 individuals were investigated with ultrasonography for the presence of a popliteal cyst. Participants included healthy volunteers, patients with a painful knee, and a group of patients with signs and symptoms of deep vein thrombosis (DVT). The location, thickness and content of all cysts were recorded. In addition, the popliteal fossa was dissected in four cadaver knees.

Results

The prevalence of popliteal cyst increased with age and was significantly higher in those aged over 50 years (P < 0·001). Compared with controls (incidence 3·0 per cent), cysts were more common in patients with DVT symptoms (9·5 per cent; P = 0·141) and those with painful knees (19·8 per cent; P < 0·001). All cysts were located in the posteromedial aspect of the popliteal fossa; the majority extended between the deep fascia and the medial head of the gastrocnemius muscle. At this level an area without external support of the posterior capsule was identified between the two expansions of the semimembranosus muscle from the medial side (the oblique popliteal ligament and the expansion over the popliteus muscle) and the posterior cruciate ligament from the lateral side. This area was also located in the knee dissections. No association was found between popliteal cyst and acute DVT.

Conclusion

Popliteal cysts are relatively common in patients over 50 years old with a painful knee or with signs and symptoms of DVT. They form in the posteromedial popliteal fossa because the synovial capsule does not provide anatomical support in this region.

Dissecting a popliteal cyst after failed unicompartmental knee arthroplasty

This report documents the first case of a popliteal cyst in a knee with failed unicompartmental knee arthroplasty (UKA). The cyst was treated successfully with the creation of a small communication hole between the posteromedial compartment and the popliteal cyst under direct arthroscopic visualization. This was followed by the replacement of a worn polyethylene insert via a small arthrotomy. Three months later, the popliteal mass had disappeared. This case suggests that a dissecting popliteal cyst may occur after UKA as one of the signs of a malfunction. It also suggests that treatment should be directed toward the joint and not the cyst itself.

Dissecting popliteal cyst resulting from a fragmented, dislodged metal part of the patellar component after total knee arthroplasty

Dissecting popliteal cyst is an uncommon complication after total knee arthroplasty, occurring mainly as a result of either rheumatoid arthritis or a malfunctioning knee prosthesis. Its association with a failed metal-backed patellar component has not been reported since the introduction of the resurfacing of the patella with this kind of design in 1980. We present a case of a late fracture-dislocation of the metal part of the patellar component that migrated to the posterior popliteal fossa, resulting in a cystic mass formation caused by a foreign body granuloma. The patient was treated successfully with a 2-stage operation: first, revision of the total knee arthroplasty and, second, excision of the cyst. The patient had a pain-free functional knee 7 years after surgery, with no recurrence of the symptoms or the popliteal cyst.