Localized pigmented villonodular synovitis: a rare cause of locking of the knee

Acute Post-Traumatic Locked Knee - An Unmasking of a Rare Knee Disorder

Locked knees are commonly caused by meniscal tears, floating osteochondral bodies, ruptured anterior cruciate ligament (ACL) stump, or other mechanical origins in the knee. Some locked knees occur spontaneously, while in most cases, by a preceding knee trauma. Locked knees are rarely caused by a pathological growth in the knee. More unusually is the occurrence of locked knee caused by a pre-existing pathological entity after a traumatic event. We report a rare case of locking in the knee by a pre-existing knee condition presented only after trauma to the knee. This case emphasizes that locking in the knee can be caused by a pathology that may be asymptomatic until it is revealed by a traumatic event.

Arthroscopic resection of benign tumors of the knee posterior compartment: a report of 15 cases

INTRODUCTION

The management of tumors located in the posterior compartment of the knee, whatever the nature of the tumor, remains surgical excision and can be done by open surgery or under arthroscopic control. The objective of this study was to evaluate the arthroscopic management of intra-articular tumors of the posterior compartment of the knee. The hypothesis is that tumors or tumor-like lesions confined to the posterior compartment are accessible by arthroscopy with low iatrogenic risk.

MATERIALS AND METHODS

All patients with an intra-articular tumor of the posterior compartment of the knee were enrolled between 2009 and 2013. The surgical management consisted of arthroscopic resection. Patients underwent postoperative MRI, repeated at last follow-up. The outcomes were the occurrence of complications, functional evaluation using the Lysholm Knee Scoring Scale, and the recurrence rate.

RESULTS

Fifteen patients were included. All patients had a complete resection. One case of delayed healing of the arthroscopic entry point was observed. At a mean 22months, the mean Lysholm Knee Score increased from 74 (±8.5) preoperatively to 92 (±7.7) postoperatively, a significant increase of 18 points (P=0.001). One patient had a recurrence of osteochondromatosis, requiring removal of a foreign body.

DISCUSSION

Resection of posterior intra-articular tumors of the knee using arthroscopy is possible, subject to a learning curve.

Giant Cell Tumor of the Patella Tendon Sheath Presenting as a Painful Locked Knee

Patient: Male, 26

Final Diagnosis: Giant cell tumor of the patella tendon seath

Symptoms: Efusion • locking knee • pain

Medication: None

Clinical Procedure: Arthroscopy and open resection of the tumor

Specialty: Orthopedics and Traumatology

Synovial recesses of the knee: MR imaging review of anatomical and pathological features

The knee joint is a complex anatomical structure playing host to a wide variety of pathological processes. Knowledge of the anatomy of the synovial recesses and plicae relating to the knee is important, as the appearance of pathology in these unusual locations may, even for commonly encountered conditions, lead to diagnostic uncertainty. This review article discusses the magnetic resonance imaging (MRI) anatomy of the knee joint with an emphasis on the synovial recesses and plicae. The MRI appearance of a variety of synovial and osteochondral diseases that may involve these sites is illustrated.

Postoperative management of pigmented villonodular synovitis in a single subject

STUDY DESIGN

Case report.

BACKGROUND

Pigmented villonodular synovitis (PVNS) is a rare, benign disorder characterized by idiopathic proliferation affecting the synovium of joints, tendon sheaths, and bursae. Diagnosing PVNS in the knee is difficult because the clinical presentation and symptoms mimic those of more common disorders at the joint, such as internal derangements or arthritis. Operative treatment of PVNS typically consists of arthroscopic or open synovectomy, but no reports of postoperative rehabilitation exist.

CASE DESCRIPTION

This case describes the postoperative rehabilitation of a 46-year-old female who had left knee surgery secondary to PVNS. Rehabilitation consisted of combined manual therapy, exercise, and gait training to improve function and gait, and cognitive-behavioral techniques to improve self-efficacy.

OUTCOMES

All impairments improved in 2.5 months of physical therapy to normal, and the patient estimated 80% to 90% return to function.

DISCUSSION

This patient obtained excellent outcomes in 2.5 months of physical therapy following surgery for PVNS. Although no firm conclusions can be drawn from a case report, this patient responded well to a biopsychosocial approach that combined physical therapy with cognitive-behavioral techniques.

LEVEL OF EVIDENCE

Therapy, level 4.

Bone tumors around the knee: risks and benefits of arthroscopic procedures

Although most primary bone tumors and soft tissue tumors arise around the knee joint, many patients with tumoral conditions attribute their symptoms to traumatic events. This may lead to misdiagnosis and mistakes in selection of therapeutic approach. Arthroscopy is the preferred method for diagnosis and treatment of knee joint disease, but even a minimally invasive procedure may have adverse consequences in the presence of an unsuspected neoplasm. Thus, evaluation of all patients who may benefit from knee arthroscopy requires a careful and systematic workup that consists of appropriate noninvasive imaging studies and thoughtful consideration regarding the need for magnetic resonance imaging. Arthroscopic biopsy and treatment are recommended for selected intra-articular tumors. In addition, arthroscopy is a useful adjunct during surgical treatment of patients with certain juxta-articular benign bone tumors. In this Current Concepts review, we consider the risks and benefits of arthroscopy in the presence of tumors about the knee joint.

Pigmented villonodular synovitis of the knee: disease of the popliteus tendon and posterolateral compartment

The knee joint is the most frequent location for pigmented villonodular synovitis (PVNS). Within the knee, localized PVNS is most commonly situated within the anterior compartment and is rarely found in the posterior compartment. Preoperative diagnosis is often elusive but can be improved with magnetic resonance imaging. We present a case of localized PVNS within the posterolateral compartment of the knee originating from the popliteus tendon that was not found on preoperative examination or radiological imaging.

[Pigmented villonodular synovitis of the knee joint]

Pigmented villonodular synovitis is a rare proliferative disorder of the synovial membrane most frequently found in the knee. The etiopathology of the disease is still not understood. Present terminology differentiates between a localized (LPVNS) and a diffuse (DPVNS) form. Currently, MRI is the diagnostic imaging technique of choice. The localized form (LPVNS) can be cured definitely in almost all cases by partial arthroscopic synovectomy, whereas the treatment of the diffuse form (DPVNS) is discussed controversially concerning an arthroscopic or total synovectomy by open arthrotomy. We report a case rarely found in the literature of a patient suffering from a diffuse form of PVNS localized in the right knee joint. In this case PVNS acted as a locally aggressive and destructive lesion of immense extent invading femoral, tibial and fibular bone and the whole extending muscular system. We performed a radical synovectomy by open arthrotomy. By implanting a tumor prosthesis we prevented progression of the disease. Apart from adequate diagnosis, we recommend complete and aggressive resection of the affected tissue by performing an open arthrotomy.

Clustered localized pigmented villonodular synovitis

The localized form of pigmented villonodular synovitis (PVNS) is a rare pathologic entity characterized by limited involvement of the synovium. In the knee joint, which is the most commonly affected joint, the disorder generally presents as a single nodular lesion, or rarely as 2 or 3 multiple nodular lesions into the joint. We report 2 cases of localized PVNS in which multiple nodules were clustered in a limited patella fat pad area. Clustered, multiple nodular lesions in a limited area suggested to us to consider a variant of localized forms.

Arthroscopic treatment of solitary benign intra-articular lesions of the knee that cause mechanical symptoms

PURPOSE

Most cases of knee locking and giving-way are caused by meniscal tears, loose bodies, or chondral lesions. Intra-articular benign tumors or tumor-like lesions can present with symptoms that resemble acute mechanical derangement. From a database of 2,200 arthroscopic interventions, 19 cases of intra-articular masses that presented with catching and locking symptoms in the knee were retrospectively analyzed.

TYPE OF STUDY

Case series.

METHODS

Our review revealed 33 patients with benign intra-articular masses in the knee joint. Nineteen of these individuals had sought medical attention for mechanical symptoms of catching or locking. The other 14 patients had a variety of symptoms including pain, swelling, and limitation of knee motion, but did not have mechanical symptoms. Age, sex, history of trauma, knee pain and effusion, medical illnesses, physical examination, arthroscopic findings, and pathologic findings were noted.

RESULTS

The average age of the 6 male and 13 female patients was 37.5 years (range, 18 to 58 years). Preoperative magnetic resonance imaging confirmed the diagnosis in 7 cases and 12 cases were diagnosed during knee arthroscopy. The mean follow-up time after surgery was 52.5 months (range, 6 to 120 months). Pathologic examination of the lesions revealed 15 cases of localized pigmented villonodular synovitis (79%), 1 lipoma arborescens (5%), 1 pseudocyst (5%), and 2 nonspecific synovial masses (11%). None of the lesions showed malignant transformation.

CONCLUSIONS

Solitary benign intra-articular lesions should be considered a rare cause of mechanical knee symptoms. Localized pigmented villonodular synovitis originating from the extensor mechanism or fat pad is the most common solitary intra-articular mass lesion in the knee and usually arises in the patellofemoral compartment. Recurrence has not occurred in our series, which includes 14 of 19 patients with greater than 24 months follow-up.

LEVEL OF EVIDENCE

Level IV.

Differential diagnosis of tumours and tumour-like lesions of the infrapatellar (Hoffa?s) fat pad: pictorial review with an emphasis on MR imaging

A variety of intrinsic and extrinsic tumours and tumour-like conditions may affect the infrapatellar (Hoffa's) fat pad (IFP). MR imaging is the technique of choice in evaluating these conditions, but correlation with radiographs is important to identify those lesions producing mineralization. This pictorial review illustrates the spectrum of mass-like lesions that can affect the IFP, emphasizing the radiographic and MR findings that suggest a specific diagnosis.

Isolated posterior cruciate ligament rupture presenting as a locked knee

Mechanical symptoms in the knee, especially locking, are most commonly associated with meniscal pathology. We present an atypical case of locking of the knee secondary to an isolated posterior cruciate ligament tear.

Localized pigmented villonodular synovitis of the knee

Eight patients with localized pigmented villonodular synovitis (LPVNS) of the knee were treated with arthroscopic and open techniques, with diagnosis confirmed by histological examination. Average patient age was 29 years (range: 13-50 years). At arthroscopy, all lesions except one were in the anterior compartment of the involved knee. Treatment consisted of complete local excision with partial synovectomy. This procedure was completed arthroscopically in seven patients. No recurrence was reported at average 24-month follow-up (range: 12-33 months). Arthroscopy is a valuable tool in the diagnosis and treatment of LPVNS.

Result of arthroscopic treatment of pigmented villonodular synovitis of the knee

PURPOSE

We report 10 years' experience in arthroscopic treatment of pigmented villonodular synovitis (PVNS) of the knee in a series of patients affected by the localized or diffuse form of the disease. The purpose of the study is to critically examine the results of arthroscopic synovectomy in the knee affected by PVNS, to determine the safety and effectiveness of the procedure.

TYPE OF STUDY

Retrospective case analysis.

METHODS

The study population consists of 19 patients, with an average follow-up of 60 months (minimum, 12; maximum, 128). All patients underwent knee arthroscopy. The 3 standard portals were used; posteromedial and posterolateral portals were added if required. Four patients were affected by localized PVNS and were subject to partial synovectomy with excision of the pathologic tissue. The remaining 15 patients presented a diffuse form of PVNS; 7 of them underwent extended arthroscopic synovectomy and 8 underwent partial synovectomy. The diagnosis was confirmed by synovial biopsy.

RESULTS

In the group affected by the localized form of PVNS, the arthroscopic local excision resulted in a complete and persistent regression of the pathology. Among the patients affected by the diffuse form of PVNS, clinical results were better and the recurrence rate was lower in the group treated with extended synovectomy. No relevant complications were encountered. In particular, no cases of infection, stiffness, or neurovascular lesions were seen.

CONCLUSIONS

Arthroscopic synovectomy is an appropriate treatment for knee PVNS. Extended synovectomy must be performed in all cases of diffuse PVNS.

Acute traumatic extension deficit of the knee

The purpose of this study was to evaluate the events leading to acute traumatic extension deficit of the knee and the arthroscopic findings in these patients. A total of 78 consecutive patients treated in the Turku university hospital during the years 1994-1996 were included. The mean annual incidence of acute traumatic extension deficits of the knee in our study was 1.1 per 10 000 inhabitants. The single most common (33%) event causing the extension deficit was non-sports related twisting of the knee. Various sports related activities accounted for 42% of the extension deficits, and soccer was the most common sport in this group. In conclusion, acute traumatic extension deficit of the knee is usually a sign of serious intra-articular damage, and the most likely finding (in 82% of the patients in our study) is either a meniscal rupture, an anterior cruciate ligament (ACL) rupture, a patellar dislocation, or a combination of these. The lesions in these knees require prompt evaluation by an orthopaedic surgeon mainly because of the high number of bucket-handle and menisco-capsular insertion ruptures of the menisci, which are possibly suitable for repair.

Localized pigmented villonodular synovitis in an unusual location in the knee

PURPOSE

Localized pigmented villonodular synovitis (LPVNS) is a rare lesion that can affect any joint, although it is most frequently found in the knee. Clinically, it is difficult to diagnose. Radiographs are usually within normal limits.

TYPE OF STUDY

Case series.

METHODS

We present a series of 9 cases of LPVNS of the knee in 9 patients with an average age of 36 years. In 7 of the 9 cases, the lesions were in an an unusual location, 4 in the fat pad and 3 in the posterior compartment of the knee. The other 2 cases were located in the meniscocapsular junction and the intercondylar notch, respectively. The mean time from the onset of symptoms to diagnosis was 2.26 years. Magnetic resonance image (MRI) provided a characteristic image that helped with diagnosis and localizing the lesion in all cases.

RESULTS

Complete resection of the lesion using arthrotomy was performed in 4 cases and resection assisted using arthroscopy was performed in 5. All cases had an excellent result. There were no signs of clinical or MRI recurrence after a mean follow-up of 36 months.

CONCLUSIONS

LPVNS of the knee is a rare lesion. MRI provides the basis for diagnosis. Complete resection using arthrotomy or arthroscopy is the treatment.

Radiologic case study. Pigmented villonodular synovitis

Pigmented villonodular synovitis is a benign, locally aggressive disorder characterized by a unique clinical radiographic, and histopathologic presentation. While it is considered to be a rare disorder, a delay in diagnosis and treatment can potentially result in severe disruption of joint function due to subchondral invasion. Once the diagnosis is confirmed, treatment should consist of complete synovectomy. Recurrence is common, but malignant transformation is rare. The etiology of PVNS is still unknown, and perhaps its future discovery will assist in the definitive treatment of this disorder.

Arthroscopic treatment of tumor-like lesions of the knee joint: Localized pigmented villonodular synovitis and ganglion cyst of the anterior cruciate ligament

We present the arthroscopic treatment of a case of localized pigmented villonodular synovitis that led to increasing restriction of knee flexion and the case of a ganglion cyst within the anterior cruciate ligament causing unspecific pain. Both pathologies could be resected arthroscopically with complete relief of symptoms and no recurrence. In cases with unspecific clinical signs and intra-articular masses shown on magnetic resonance imaging, arthroscopy is the next therapeutic step. Localized tumor-like lesions can often be excised without recurrence in the same session.

Localized pigmented villonodular synovitis as a rare cause of chronic anterolateral ankle pain in an equestrienne

An unusual case of localized pigmented villonodular synovitis of the ankle as a rare cause of chronic anterolateral ankle pain in a 16-year-old horsewoman is presented. Intra-articular nodular forms of pigmented villonodular synovitis can only be diagnosed arthroscopically, macroscopic and microscopic aspects being typical. We believe that this lesion is more likely a reactive process secondary to repetitive microtrauma rather than a true neoplasm. Our patient presented with pathology in the left ankle, the side by which one mounts and dismounts a horse, forcing, in both activities, ankle dorsiflexion. Moreover, an English saddle was used by our patient, upon which one rides with the ankle maintained in dorsiflexion. At arthroscopy, the soft-tissue mass was seen to be entrapped in the joint between the talus and the tibia at dorsiflexion of the ankle. This had caused a slowly progressive enlargement of the lesion because of fibrosis resulting from reactive inflammation associated with this repetitive microtrauma, thus causing irritation, pain, and synovitis due to impingement.

Localized pigmented villonodular synovitis presenting as recurrent dislocation of the patella

A 31-year-old woman presented with a 1-year history of recurrent dislocation of the patella. On examination, she was found to have a mass at the medial patellofemoral joint line. Arthroscopy showed this to be a vascular synovial tumor extending into the medial patellofemoral joint and causing lateral deviation of the patella. The mass was resected with resolution of her symptoms and histologic examination showed this to be pigmented villonodular synovitis. There are an increasing number of case reports of these lesions causing varying mechanical symptoms in the knee and they should be considered as a differential diagnosis.

MR appearances of the locked knee

This review illustrates the MR appearances of commonly encountered problems that can present as a "locked knee", as well as several unusual causes. Internal derangement of menisci, particularly bucket handle tears, predominate. Loose bodies as a result of trauma/degeneration and lesions such as cysts of the cruciate ligaments and focal pigmented villonodular synovitis are also illustrated. While meniscal tears are the major cause of "locked knee" in clinical practice, interference with normal knee kinematics is non-specific with regard to the diagnosis. Emphasis is therefore given to less frequently seen abnormalities that lead to a mechanical block of knee extension.

Magnetic resonance imaging evaluation and arthroscopic resection of localized pigmented villonodular synovitis of the knee

Diagnosis of localized pigmented villonodular synovitis is clinically difficult, and plain radiographs are usually normal. This article presents five patients with localized pigmented villonodular synovitis of the knee. Symptoms suggested a meniscal lesion in three patients and a loose body in two. Magnetic resonance imaging performed prior to arthroscopic resection revealed a preoperative diagnosis of a tumor in all five patients. Magnetic resonance imaging is a valuable clinical tool for the assessment of intra-articular soft-tissue tumors of the knee that may otherwise be misdiagnosed.