Synovial chondromatosis presenting as a pathological fracture of the femoral neck in an 89-year-old woman--a case report

Arthroscopic surgery for synovial chondromatosis of the hip: a systematic review of rates and predisposing factors for recurrence

PURPOSE

Synovial chondromatosis of the hip is a benign condition whereby pain and functional limitations occur due to numerous intra-articular osteochondral fragments produced by a metaplastic synovium. Recurrence not only worsens morbidity but may lead to malignant transformation. With reported recurrence rates as high as 22% by open surgical approaches and given the increasing use of hip arthroscopy for the treatment of synovial chondromatosis, we sought to quantify the recurrence rate after arthroscopy, as well as identify predisposing factors for recurrence.

METHODS

Using predetermined inclusion criteria, 3 electronic databases--Embase, Medline, and PubMed-were searched for relevant articles addressing arthroscopic surgery for synovial chondromatosis of the hip across all available dates up to and including February 16, 2014. A hand search of the reference sections of the included studies was also completed. Article screening was conducted in duplicate. Reviewer agreement statistics and descriptive statistics of the included studies are presented.

RESULTS

From an initial retrieval of 2,542 studies, 14 studies satisfied the criteria for inclusion. A total of 197 patients (age range, 13 to 81 years) underwent hip arthroscopy for removal of intra-articular osteochondral fragments and synovectomy to alleviate both mechanical symptoms and pain. Follow-up periods ranged from 1 to 184 months, with approximately 7.6% of patients (15 of 197) lost to follow-up. The recurrence rate after hip arthroscopy was 7.1% (14 of 197), and the rate of minor complications, such as perineal and pedal neurapraxia, was 1%.

CONCLUSIONS

For synovial chondromatosis of the hip, arthroscopic removal of osteochondral fragments with synovectomy is both safe and effective, with a mean recurrence rate of 7.1%.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Hip resurfacing as treatment for synovial chondromatosis

Synovial chondromatosis is a rare condition of metaplastic cartilage development in the synovial membrane of joints. These foci can form free bodies and lead to mechanical arthrosis. The precise etiology is unknown. All synovial joints can be affected, with the hip and knee being most common. Patients with synovial chondromatosis are usually in their fifth decade and typically present with mechanical pain and diffuse swelling. Due to its rarity and nonspecific manifestations, diagnosis of synovial chondromatosis is often delayed until significant mechanical damage and arthrosis has occurred.Controversy exists regarding surgical treatment of synovial chondromatosis, especially with regard to the hip. Localized disease can be treated with resection of affected synovium (possibly arthroscopically), whereas patients with generalized disease require complete, open synovectomy. With articular damage, total hip replacement has been advocated along with synovectomy.This article presents a case of a young man with painful hip synovial chondromatosis who was successfully treated with hip resurfacing and synovectomy after failed hip arthroscopy. Hip resurfacing provides the surgeon with the opportunity to address not only local or generalized synovial disease, but articular damage as well. Furthermore, its bone-preserving properties make this option attractive in the management of this younger patient population. We feel resurfacing has a role in the surgical treatment of synovial chondromatosis. To our knowledge, this is the first case of hip resurfacing arthroplasty for the definitive treatment of synovial chondromatosis.

[Synovial chondromatosis]

Primary articular synovial chondromatosis is a benign, self-limiting neoplastic process in which hyaline cartilage nodules form in the synovial tissue. The disease most frequently affects the knee in men, followed by the elbow. The basic feature of this disease is a metaplastic maturation of the mesenchymal cells in the synovial membrane of a joint into cartilage. These cells mature into chondroblasts and form small nodules of cartilage in the synovial membrane. These nodules subsequently enlarge and detach to lie within the joint space. They become free within the joint as multiple small cartilaginous loose bodies nourished by the synovial fluid. The chondrocytes in the loose bodies continue to multiply, and the loose bodies grow in diameter. Calcification appears in the central zone of the loose bodies, and in some cases, enchondral ossification takes place. The operative therapy depends on the stage of the disease: synovectomy with removal of chondral fragments if active intrasynovial disease is present, and removal of the multiple chondral bodies alone in cases of late inactive disease with no synovial abnormalities. Malignant transformation is unusual and can be difficult to distinguish from benign disease.

Operative treatment of primary synovial osteochondromatosis of the hip. Surgical technique

BACKGROUND

Primary synovial osteochondromatosis of the hip, a rare benign condition characterized by multiple intra-articular osteochondral loose bodies and synovial hyperplasia, may result in mechanical symptoms and degenerative arthritis if untreated. The purpose of this study was to report the results of arthrotomy alone or combined with anterior dislocation of the hip to perform synovectomy and removal of loose bodies in patients with this condition.

METHODS

We retrospectively reviewed a consecutive series of twenty-one patients (twenty-one hips) with primary synovial osteochondromatosis of the hip treated with open surgical débridement. On the basis of the extent of extra-articular involvement as seen on preoperative magnetic resonance imaging, eight of the twenty-one patients underwent synovectomy and removal of loose bodies following anterior dislocation of the hip and thirteen underwent the same procedure with arthrotomy alone. At a mean of 4.4 years postoperatively, the patients were assessed clinically and radiographically with special attention to disease recurrence, osteoarthritis progression, and surgical complications.

RESULTS

The mean Harris hip score for the entire series of patients improved from 58 points preoperatively to 91 points at the time of the latest follow-up. Eighteen of the twenty-one patients had a good or excellent clinical result, and seventeen patients were satisfied with the result of the surgery. The clinical scores, patient satisfaction scores, and radiographic grades of osteoarthritis at the time of the latest follow-up did not differ significantly between the group treated with dislocation and the group treated without dislocation. Symptomatic disease recurred in two of the thirteen hips treated with arthrotomy alone and in none of the hips that had undergone dislocation. However, the surgical complication rate was higher in the group treated with dislocation than it was in the group treated without dislocation (p = 0.042). While patients with some signs of mild osteoarthritis at the initial procedure had a higher rate of osteoarthritis progression, severe osteoarthritis requiring arthroplasty had developed in only one patient at the time of follow-up.

CONCLUSIONS

At a mean of 4.4 years postoperatively, we found that open synovectomy and removal of loose bodies for the treatment of primary synovial osteochondromatosis of the hip is a reliable procedure that can effectively relieve symptoms. Our results also indicated that synovial osteochondromatosis may recur in patients with extensive involvement who are treated with synovectomy alone without dislocation of the hip; however, surgical complications are more likely to occur in patients managed with anterior dislocation of the hip and synovectomy.

Operative treatment of primary synovial osteochondromatosis of the hip

BACKGROUND

Primary synovial osteochondromatosis of the hip, a rare benign condition characterized by multiple intra-articular osteochondral loose bodies and synovial hyperplasia, may result in mechanical symptoms and degenerative arthritis if untreated. The purpose of this study was to report the results of arthrotomy alone or combined with anterior dislocation of the hip to perform synovectomy and removal of loose bodies in patients with this condition.

METHODS

We retrospectively reviewed a consecutive series of twenty-one patients (twenty-one hips) with primary synovial osteochondromatosis of the hip treated with open surgical débridement. On the basis of the extent of extra-articular involvement as seen on preoperative magnetic resonance imaging, eight of the twenty-one patients underwent synovectomy and removal of loose bodies following anterior dislocation of the hip and thirteen underwent the same procedure with arthrotomy alone. At a mean of 4.4 years postoperatively, the patients were assessed clinically and radiographically with special attention to disease recurrence, osteoarthritis progression, and surgical complications.

RESULTS

The mean Harris hip score for the entire series of patients improved from 58 points preoperatively to 91 points at the time of the latest follow-up. Eighteen of the twenty-one patients had a good or excellent clinical result, and seventeen patients were satisfied with the result of the surgery. The clinical scores, patient satisfaction scores, and radiographic grades of osteoarthritis at the time of the latest follow-up did not differ significantly between the group treated with dislocation and the group treated without dislocation. Symptomatic disease recurred in two of the thirteen hips treated with arthrotomy alone and in none of the hips that had undergone dislocation. However, the surgical complication rate was higher in the group treated with dislocation than it was in the group treated without dislocation (p = 0.042). While patients with some signs of mild osteoarthritis at the initial procedure had a higher rate of osteoarthritis progression, severe osteoarthritis requiring arthroplasty had developed in only one patient at the time of follow-up.

CONCLUSIONS

At a mean of 4.4 years postoperatively, we found that open synovectomy and removal of loose bodies for the treatment of primary synovial osteochondromatosis of the hip is a reliable procedure that can effectively relieve symptoms. Our results also indicated that synovial osteochondromatosis may recur in patients with extensive involvement who are treated with synovectomy alone without dislocation of the hip; however, surgical complications are more likely to occur in patients managed with anterior dislocation of the hip and synovectomy.