Abstract

Osteoarthritis of the manubriosternal joint is a rare cause of chest pain. The diagnosis is difficult, and other serious causes of chest pain have to be ruled out first. We report one case that was treated with fusion of the manubriosternal joint using iliac crest bone graft and cervical locking plate and screws with excellent result. Pre-operative CT scan images were used to measure the screw length and the drill stop depth. In this case report, we have concluded that arthrodesis can be an effective way of treating osteoarthritis (OA) of the manubriosternal joint when other measures fail. Furthermore, the use of a cervical locking plate with appropriate and careful pre-operative planning affords a safe surgical technique, rapid pain relief and ultimately sound and asymptomatic fusion of the joint.

Case Report

A 30-year-old farmer presented with a 3-year history of gradually worsening pain around anterior chest wall over the upper sternal area. The pain was exacerbated by exercise, coughing and sneezing. The pain affected his ability to work. Examination revealed a swelling and tenderness over manubriosternal joint (MSJ). Extremes of shoulder abduction and flexion aggravated his symptoms. The general examination was otherwise unremarkable. There was no significant medical history like diabetes, hypertension and coronary artery disease. His ECG and hematological investigations like serum uric acid were within normal range. X-ray chest sternal view revealed degenerative changes in the MSJ with multiple subchondral cysts. This was confirmed by CT (Figs. 1 and 2) and MRI scanning of MSJ. Patient was initially treated with non-steroidal anti- inflammatory drugs (NSAIDs) for so many months, which showed recurrence of pain after cessation of drugs. He was then treated by intra-articular steroid injection, which reported minimal initial response to this treatment. However, his symptoms recurred within few weeks and hence the operative option was advised, which the patient was keen to take because of the severity of pain and the resultant handicap.

Operation

Pre-operative planning was done using the CT scan images to measure the screw length and the drill stop depth (Fig. 3). The operation was performed with the patient in supine position. The sternum and the angle of Louis were exposed through a midline thoracic incision. The manubriosternal joint was excised and curetted. Degenerated cartilage and hypertrophic bone at the site of the arthritic MSJ was removed. Autologous cancellous bone graft from iliac crest was used to firmly pack the defect. The MSJ was finally fixed with cervical locking plates that were contoured and secured with bicortical screws. This achieved absolute stability of the MSJ (Figs. 4 and 5).

Progress

The patient was discharged home 3 days post-operatively. On discharge, his pain was very much relieved. He graded his pain as 3/10, as compared to 9/10 prior    to  the  operation.  He  was  advised  not  to use his arms for  strenuous  activities  for initial 5-6 weeks. After six weeks, he resumed his daily routine activities. After three months, he returned to work. The patient was very pleased with the outcome of the surgery.

Discussion

Osteoarthritis (OA) is a chronic degenerative disorder characterized by softening and disintegration of articular cartilage, with reactive responses such as vascular congestion and osteoblastic activity in the subarticular bone, new growth of cartilage and bone (osteophytes) at the joint margins, and capsular fibrosis.¹

The manubriosternal joint is a cartilaginous joint (symphysis) in which the articular surfaces are covered with a thin lamina of hyaline cartilage and there is an intervening disc of fibrocartilage. Frequently (30%), cavitation appears in the disc so that the joint may appear to be synovial, but this is simply a degenerative change that does not alter the fact that the joint is a symphysis.² This probably is due to the involvement of the MSJ in systemic diseases such as rheumatoid arthritis (RA), osteoarthritis, ankylosing spondylitis, gout and psoriatic arthritis.³ The symphysis permits a small range of motion between longitudinal axes of the manubrium and body of the sternum, and also limited anteroposterior displacement. In RA, for example, the MSJ is commonly involved, but it rarely gives rise to symptoms.⁴

OA of the MSJ is very rare and may pose a diagnostic dilemma and other more serious causes of chest pain need to be ruled out first. Joint arthrodesis for OA is a known treatment option. Lièvre and Bauman performed curettage of the joint surface in two cases of isolated MSJ arthrosis with good results in only one.⁵ Litchman and colleagues reported performing arthrodesis of the MSJ in a case of post-traumatic degenerative arthrosis of the MSJ. In that procedure, they carried out resection of   a portion of the joint and reversing a sliding bone graft to traverse the joint. They reported a satisfactory outcome with regard to pain relief, but the patient could not return to heavy manual work afterwards.⁵ Shewring and Carvell also reported performing arthrodesis of the MSJ for recurrent gout. In this report,  the arthrodesis was performed through a transverse incision with only cancellous bone grafting done without joint fixation.⁶ Al-Dahiri and Pallister also have reported performing arthrodesis of MSJ in a case of osteoarthritis using double locking compression plates with good results.⁷

Conclusion

Joint fusion,  using  a   locking  plate,  is a better treatment option for  OA  of MSJ. The locking plate provides fixed angle stability as the screws lock in the plate. Therefore, it is a sound choice of fixation at an area, which cannot be firmly immobilized because of movements of respiration. Furthermore, loosening and migration of the metalwork is unlikely because that would require all the screws on one side of the arthrodesis to fail at the same time, which is a remote possibility. Cervical locking plate being a thin plate provides additional advantage of avoiding hardware prominence over sternum. The use of CT scan images preoperatively to measure screws length and drill stop depth is must to provide safety to underlying vital structures.

References

1. Textbook of Kelly WN, Harris ED, Ruddy S, Sledge CB (Eds), 6th Edition, Volume 1, WB Saunders 2001:p.1409.
2. Susan Standring.  Gray’s anatomy,  39th  Edition,  Elsevier  Churchill  Livingstone  2005:p.959.
3. Sinnatamby CS.  In:  Last’s  Anatomy  Regional  and  Applied,  10th  Edition,  Churchill  Livingstone  1999: 175.
4. Double A, Clarke AK. Symptomatic manubriosternal joint involvement in rheumatoid arthritis. Ann Rheum Dis 1989;48(6):516-7.
5. Litchman HM, Silver CM, Simon SD, et Post-traumatic degenerative arthrosis in the manubriosternal joint. Clin Orthop Relat Res 1969;67:111-5.
6. Shewring DJ, Carvell JE. Arthrodesis for recurrent manubriosternal gout. J Bone Joint Surg Br 1991;73(2):341.
7. Al-Dahiri A, Pallister I, Arthrodesis for osteoarthritis of the manubriosternal joint. Eur J Cardiothorac Surg 2006;29(1):119-21.

Figurs 1 and 2. Radiological and CT scan showing osteoarthritic changes of MSJ.

Figure 3. CT scan images to measure the screw length and the drill stop depth.

Figurs 4 and 5. MSJ fixed with cervical locking plate and screws.