Efficient Extraction of Synovial Chondromatosis Utilizing the Loose Body Vacuum

Abstract

Background:

Synovial chondromatosis is a benign proliferation of the synovial membranes surrounding joints and tendon sheaths that may cause serious joint instability and dysfunction. If left untreated, loose bodies generated within the joint can lead to accelerated joint destruction. Arthroscopic synovectomy with loose body removal has been recommended in certain cases to limit the rate of recurrence. Past techniques have utilized suction as well as manual removal of larger loose bodies.

Indications:

The patient had extensive right hip synovial chondromatosis as well as femoral acetabular impingement and a labral tear. Thus, she was indicated to receive arthroscopic labral repair along with a femoroplasty and removal of foreign bodies to return functionality and prevent future joint damage.

Technique Description:

This technique uses a large 5.5-mm bur with the inner bur piece removed from its sleeve. Usage of the sleeve as a vacuum for suctioning small and large loose bodies allows for the minimization of manual removal and soft tissue disruption.

Results:

Arthroscopic bur sleeves allowed for efficient removal of loose bodies in the setting of synovectomy and symptomatic synovial chondromatosis.

Discussion/Conclusion:

For this case, removal of synovial chondromatosis utilizing the loose body vacuum resulted in good clearance of larger loose bodies while minimizing soft tissue disruption. Utilization of the same instrument for both arthroscopic debridement and loose body removal is both efficient and cost-effective.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we present the efficient extraction of synovial chondromatosis utilizing a 5.5-mm arthroscopic bur cannula, which we will refer to as the “loose body vacuum.” The procedure was performed by lead surgeon Dr. Shane Nho and his team at Midwest Orthopaedics at Rush.

Here are our disclosures.

Background

Synovial chondromatosis is a rare, noncancerous overgrowth of the synovial membrane that varies in size and is usually found free-floating within a joint. Buildup of these growths can lead to joint pain and dysfunction, potentially predisposing patients to long-term joint destruction if left untreated. ³

Treatment in mild cases can be conservative with nonsteroidal anti-inflammatory drugs, physical therapy, and cryotherapy. However, for definitive treatment, surgical removal of loose bodies is recommended.^7,11 In isolation, synovectomy is controversial for synovial chondromatosis removal, as studies have shown no benefit, while other studies have shown decreased rates of recurrence. ¹⁰ In addition, arthroscopic or open approaches are also disputable. The arthroscopic approach has been shown to lower morbidity and have postoperative benefits such as decreased pain and quicker time to rehabiliation.^4,8 Arthroscopically, small loose bodies that are just a few millimeters in width can be removed with suction or lavage, while larger loose bodies that are centimeters in width typically require manual removal. ⁵ Synovial chondromatosis has also been reported to present alongside cam-type femoroacetabular impingement syndrome (FAIS). ¹ In these cases, loose body removal alongside typical FAIS treatment was shown to improve patient-reported outcomes (PROs). ⁹

Indications

Here we present the case of a 28-year-old woman with no medical history presenting to our clinic with right hip pain that has been ongoing for 4 years. The pain was primarily located in her right groin region and had not been related to any traumatic events. She reports that the pain did not improve despite physical therapy and anti-inflammatory treatments. She was having trouble participating in her usual sports activities due to her pain.

On physical examination, the patient’s passive range of motion (ROM) was intact. There was some weakness in right hip flexion, but otherwise, her strength was intact. She had positive subspine pain and a positive flexion, adduction, internal rotation (FADIR) test. She also experienced pain on rotation from the 1- to 3-o’clock positions. There was no associated numbness or other neurologic deficits.

Three views of the right hip were obtained, including anteroposterior (AP), false profile, and 90° Dunn. Radiographs showed well-preserved joint space and no evidence of fractures, dislocations, or soft tissue abnormalities. As you can see here on the AP view, several multifocal, round, calcific loose bodies were found. The lateral center edge angle was measured to be 29°, suggesting normal coverage. The alpha angle was measured to be 60°, suggesting a cam deformity and femoroacetabular impingement. On magnetic resonance imaging (MRI), the same loose bodies can be seen surrounding the joint within the capsule. In addition, MRI revealed an acetabular labral tear without other surrounding soft tissue abnormalities.

The patient was deemed to have FAIS, an acetabular labral tear, and extensive synovial chondromatosis. Given her lack of improvement with conservative management, surgical intervention was recommended, and the patient was scheduled to undergo a right hip arthroscopy to address her pathology.

Technique Description

The surgical plan included arthroscopic synovectomy and any necessary debridement following the initial capsulotomy to address both the synovial chondromatosis and associated loose bodies. A segmental labral repair was planned to address her labral tear, in addition to a femoral osteochondroplasty to address her cam deformity and, finally, capsular plication to repair her initial capsulotomy.

Immediately after entering the capsule, the cartilaginous formations from her synovial chondromatosis can be seen. These nodules that have broken free are now free-floating within the capsular space, causing pain, stiffness, and dysfunction. The pressure of the arthroscopy pump was preset to a maximum of 70 mm Hg, which allowed for a controlled suction and extraction of loose bodies throughout the procedure. Initially, a 3.5-mm arthroscopic shaver was trialed to break up the nodules within the joint space. However, larger nodules were unable to be broken down or would become lodged within the instrument. Additionally, the use of the shaver would simply cause some of the larger bodies to float away due to the agitation it causes. It should be noted that smaller nodules were able to be collected by the 3.5-mm shaver and captured in a catch container. We then trialed removing the shaver from its cannula. However, the 3.5-mm cannula failed to extract both larger nodules and clumps of smaller nodules.

Knowing that size was an issue, we then utilized the cannula of a 5.5-mm arthroscopic bur. Here you can see us removing the bur from its cannula. In the following scope footage, we demonstrate our ability to efficiently vacuum and remove many large loose bodies throughout the central and peripheral compartments. Given its abilities, we term the use of this instrument as the loose body vacuum.

At this point in the procedure, the posterior compartment of the capsule was then visualized containing further extensive nodule formation secondary to synovial chondromatosis. The loose body vacuum extracted large clumps of nodules with ease compared to prior trials with smaller cannulas. This technique allowed us to clear the field of both visually identified and hidden loose bodies from within the hip capsule.

To aid in the prevention of further nodule formation secondary to synovial chondromatosis, radiofrequency ablation was utilized to ablate the synovium. Synovectomy was performed along the internal capsule as well as the intracapsular bony surface of the femur.

During the femoral osteochondroplasty portion of the hip arthroscopy, further nodules that were hidden were made evident due to the agitation caused by the bur’s revolutions. The 5.5-mm bur alone was unable to clear the remaining loose bodies. At this point, the femoral osteochondroplasty was paused to address the presence of further loose bodies obstructing visualization of the arthroscope. With the loose body vacuum, the remaining nodules were easily identified and extracted.

At the conclusion of the procedure, the anterior and posterior compartments of the capsule were then visualized a final time utilizing the loose body vacuum to extract any residual nodules that may have been missed. Also, any remaining debris from the procedure could be evacuated using the loose body vacuum at this time.

Results and Discussion

Here are the instruments depicted on the back table. On the bottom, the initial 3.5-mm shaver used for soft tissue debridement is shown separated from its cannula. Above the shaver, the 5.5-mm bur head used for bony debridement is also shown separated from its cannula. At the top is the cannula of the arthroscopic bur, which was utilized as the loose body vacuum.

Here we would like to highlight some technical pearls that may help avoid complications. The utilization of an arthroscopic approach rather than an open approach reduces complication risk, given its inherent benefits of smaller incisions, less blood loss, and faster recovery times. ¹² Additionally, the synovectomy alongside loose body removal aids in preventing the recurrence of these nodules from the synovium. ¹² Also, by using all standard hip arthroscopy portals, including the anterolateral portal, mid-anterior portal, and distal anterolateral portal, the entirety of the hip can be examined. By alternating the camera and arthroscopic instruments between these portals, loose bodies can be identified in all compartments of the hip joint and capsule. Finally, by performing a dynamic adjustment of the hip during the operation, any hidden loose bodies can be removed and allow the surgeon to fully visualize the field.

Rehabilitation protocols after loose body removal follow similar standards of procedure to hip arthroscopy with labral repair, femoral osteochondroplasty, and capsular plication. ⁶ Phase 1 consists of the first 6 postoperative weeks, when ROM is restricted with an abduction brace. During the first 2 weeks, patients are restricted to flat-foot partial weightbearing with crutch or walker assistance and gradually progress to weightbearing as tolerated for the remainder of phase 1. Patients graduate from phase 1 once they are able to achieve pain-free activities of daily living and their passive hip ROM equates to 80% of the contralateral side. Phase 2 spans from postoperative weeks 6 through 12, when ROM and weightbearing restrictions are lifted. Additionally, strengthening and gait training are initiated. Patients graduate from phase 2 once they are able to ambulate pain-free without assistive devices, have pain-free ROM, achieve hip strength 80% to the contralateral side, and demonstrate minimal to no compensation with the use of stairs or single-leg movement tasks. Phase 3 includes the introduction of functional training and the return to preoperative activities. Patients graduate from phase 3 once they achieve less than 10% side-to-side differences on both medial and lateral triple-hop tests, can perform three 60-second prone and side planks, and achieve hip strength 90% to the contralateral side. Phase 4 entails the return to sport. Finally, patients graduate from phase 4 once they can perform activities without compensation, decreased strength or ROM, and pain.

The benefits of utilizing the loose body vacuum include its efficiency and ease of use for removing larger loose bodies without the need for manual extraction. The surgical view is enhanced by the efficient removal of these loose bodies, improving overall surgical precision. The bur is a common instrument used in arthroscopic surgery. Thus, its utilization for vacuum and lavage without the need for additional instruments minimizes overall costs. In addition, the use of a cannula allows for the extraction of whole chondromas. In turn, this allows for accurate measurements of the chondromas’ true pathologic size following their removal.

In a case series evaluation by Ferro and Philippon, ² 2.5-year follow-up outcomes were assessed after the arthroscopic treatment of synovial chondromatosis by manually removing loose bodies with an arthroscopic shaver and grasper or washing them away. This was subsequently followed by synovectomy with a shaver and radiofrequency ablation. The authors demonstrated significant improvement in most of their collected PROs at a 2.5-year follow-up. Two of their 23-patient cohort underwent subsequent hip revisions demonstrating recurrence of loose bodies with the same 2 patients undergoing conversion to total hip arthroplasty later in their follow-up period. ²

In a case series evaluation by Zhu et al, the arthroscopic treatment of synovial chondromatosis utilizing only a shaver and ablation technique yielded significant improvement of PROs and achievement of the minimal clinically important difference at a 4-year follow-up with durability of these results at an 8-year follow-up. However, residual loose bodies were found on postoperative computed tomography (CT) scans 1 day after surgery in 14 of 23 patients who demonstrated loose bodies on a preoperative CT scan. Over the duration of their follow-up period, only 1 of these patients with postoperative loose bodies on CT scan required subsequent revision hip arthroscopy. ¹³

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