Approach Considerations
Patients who have recurrent painful effusions, mechanical symptoms, or both as a consequence of synovial chondromatosis refractory to conservative intervention are candidates for surgical intervention.
Contraindications for arthroscopic surgery for synovial chondromatosis are few. Only joints amenable to arthroscopy (eg, knee, shoulder, wrist, and elbow) are considered. When large loose bodies are abundant, some authors have favored open excision, citing technical difficulty with the arthroscopic approach. Patients must be deemed appropriate candidates for surgery from a medical perspective. Finally, regional or general anesthesia may be used, depending on the patient's health and on the preference of the treating surgeon and the anesthesiologist.
Medical Therapy
Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used along with transcutaneous therapies (eg, ultrasound and thermal therapies) for reduction of inflammation. Patients with primarily mechanical symptoms do not benefit significantly from nonoperative therapy. One case report found radiotherapy to be a successful modality when used for synovial chondromatosis of the knee refractory to several previous surgical interventions. [49]
Surgical Therapy
The traditional surgical approach consisted of an open arthrotomy of the joint, with removal of all loose bodies and either a partial or a full synovectomy. With surgical advances and increasing surgeon familiarity with arthroscopic techniques, this approach has largely been abandoned in favor of arthroscopic techniques.
At present, standard treatment consists of arthroscopic examination and excision of loose bodies, with limited synovectomy of involved synovium only. There have been documented cases of concomitant femoral acetabular impingement and synovial chondromatosis, with some authors advocating a surgical hip dislocation to best address all pathologic features. [50]
Preparation for surgery
Patients in whom findings from the history, physical examination, plain radiography, and magnetic resonance imaging (MRI) are consistent with a diagnosis of synovial chondromatosis requiring surgical intervention are referred for a preoperative medical evaluation and clearance for surgery.
Frank discussion of the risks of arthroscopic surgery should address rates of infection (< 1%), thromboembolic disease (1-3%), iatrogenic neurovascular injury (< 1%), complications related to anesthesia, and recurrence of symptoms that necessitate further surgery (0-20%).
Consent is obtained for surgical intervention on an elective basis.
Operative details
After general anesthesia is induced, the affected limb is correctly identified and examined with the patient under anesthesia. If multiple loose bodies are present, limited passive range of motion (ROM) or crepitus may be present. Examination of ligamentous stability typically yields normal findings. The procedure is performed as follows.
A nonsterile thigh tourniquet is applied. The affected leg is surgically prepared to the level of the tourniquet.
Standard arthroscopic portals are established in the medial suprapatellar and medial and lateral parapatellar locations. When access to the posterior compartment of the knee is required, a posteromedial portal should be established. The surgeon should be comfortable with establishing this portal, and he or she must be aware of the increased potential for damage to the saphenous nerve superficially and to the popliteal artery and tibial nerve posteriorly.
A 30° arthroscope is inserted through the lateral parapatellar portal, and diagnostic arthroscopy is performed. When the arthroscope is introduced, abundant round cartilaginous bodies are typically present, both free in the joint and embedded in the synovial lining (see the image below). In primary synovial chondromatosis, the articular surfaces are typically normal. In secondary synovial chondromatosis, chondromalacia or osteochondral defects reflective of underlying disease may be present.
Arthroscopic graspers are used to remove all free loose bodies. Large or pedunculated lesions embedded in the synovium are excised by using arthroscopic graspers and shavers. (See the images below.) A large outflow cannula can be helpful for extracting loose cartilaginous pieces. All specimens are sent to a pathologist for histologic evaluation.
The arthroscopic instruments are withdrawn, and the portals are closed with monofilament nonabsorbable sutures. A sterile dressing is applied, and the knee is placed in an immobilizer. The patient is transferred to the recovery room for observation and recovery from anesthesia.
Postoperative Care
The patient is discharged from the surgical suite with narcotic pain medication, enteric-coated aspirin for deep venous thrombosis prophylaxis, and an NSAID. Pathology results are carefully followed up. Immediate full weightbearing is permitted in a knee immobilizer, with instructions to elevate and apply ice to the knee for the first 3-7 days.
Complications
The most common complications arising after arthroscopic surgery for synovial chondromatosis include stiffness and recurrence of mechanical symptoms due to loose-body generation. In most series, the rates of recurrent symptoms that necessitated repeat arthroscopic surgery were lower than 20%. With aggressive postoperative rehabilitation, use of the arthroscopic approach typically helps prevent stiffness.
Long-Term Monitoring
The patient is seen for a follow-up visit 3-7 days after surgery for evaluation of surgical wounds. Sutures are removed, and sterile bandages (eg, Steri-Strips) are applied.
Physical therapy for full active, active-assisted, and passive ROM begins. When full ROM is achieved (target time, 3 weeks after surgery), the therapist is instructed to focus on quadriceps strengthening. Full return to activity can be anticipated by 6-8 weeks after surgery.
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Arthroscopic appearance of synovial chondromatosis loose bodies in shoulder.
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Arthroscopic shaver during attempted removal of loose bodies.
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Sagittal T2-weighted MRI through knee in adult with synovial chondromatosis demonstrates abnormal signal intensity in suprapatellar pouch. Also note hypertrophic synovium in intercondylar notch region and normal posterior cruciate ligament.
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Sagittal T2-weighted MRI of patient with synovial chondromatosis. Note hypertrophic synovium and normal anterior cruciate ligament.
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Sagittal T1-weighted MRI of knee in patient with synovial chondromatosis.
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Coronal T2-weighted MRI of patient with synovial chondromatosis demonstrates punctate areas of low intensity within synovial fluid.
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Coronal T2-weighted MRI of knee in patient with synovial chondromatosis.
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Typical plain radiograph of knee in patient with synovial chondromatosis. No abnormalities are noted.
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Arthroscopic image of pedunculated synovial chondromatosis in knee.
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Arthroscopic image of pedunculated synovial chondromatosis in knee.
