» Comparing Septic Arthritis of the Shoulder and Hip in Children
Comparing Septic Arthritis of the Shoulder and Hip in Children

Physical Therapy in Grapevine for Pediatric

Most people are familiar with strep throat or a staph infection in children. But these bacteria can enter the bloodstream and travel throughout the body. For some as yet unknown reason, the bacteria take up residence in the joints and cause a septic (infectious) arthritic response. The child develops a fever and joint pain. Most often the hip or knee is affected. But sometimes the shoulder or elbow becomes septic. Movement of the affected extremity can hurt. If the arm is affected, the child may stop using it. If the leg is affected, the child may develop a limp or stop standing/walking on that side.

This is the first published study comparing the results of treatment for the more common hip septic arthritis versus the rare shoulder septic arthritis. The results are based on a small group of children (23 total) treated over a period of six years in two children's hospitals in Texas. All of the children were between ages seven months to 12 years old. They were all treated with antibiotics and surgical drainage.

Treatment is imperative in order to avoid complications like bone deformity, joint dislocation, osteomyelitis (bone infection), and halting growth that can result in limb length differences of the infected arm or leg. Surgery to drain the pus and infection from the joint and clean it out may have to be repeated more than once. In this study, up to four procedures were needed for some of the children with septic arthritis of the shoulder. Children with hip septic arthritis were more likely to respond after one operation. That's probably because shoulder septic arthritis is harder to diagnose than hip septic arthritis. So, the diagnosis can be delayed. By that time, the infection is much more powerful with more bacteria present.

Clinical results were measured by pain, range-of-motion, joint stability, and number/severity of complications. X-rays were compared looking at the presence of osteomyelitis, joint destruction, and pathologic fractures. Other data collected and compared included blood lab values (indicators of inflammation and infection), number of surgical procedures needed, number of days in the hospital, and type and duration of antibiotics used.

In general, shoulder septic arthritis was much more problematic. The children in the shoulder group had more complications, stayed in the hospital longer, and suffered more pathologic fractures. Pathologic fractures means the bone breaks without any trauma. Children with shoulder septic arthritis were more likely to have other joints infected as well. Osteomyelitis is more common in patients with shoulder septic arthritis. Treatment takes longer with the shoulder but in the final analysis, the results seem to even out.

At the final follow-up none of the children in either group (hip or shoulder) had any evidence of active infection. Their blood values had returned to normal. The authors suggest that earlier diagnosis of shoulder septic arthritis would probably make a difference. But right now, there is no way to predict with accuracy when septic arthritis of the shoulder is developing. There is a clinical prediction rule for the hip. Once that was developed, the rate of complications with hip septic arthritis dropped from 40 per cent down to five per cent. Early recognition of the problem and treatment meant less damage to the growth plate of the joint and better final outcomes in terms of hip motion and function.

Until a similar guideline can be developed for the shoulder, there are some general risk factors to pay attention to for septic arthritis in any joint. Children with diabetes, sickle cell disorders, and immune system deficiency seem to be at greater risk of staph and strep infections that can then spread to the joints. Babies (less than three months old) are more likely to have a poor result even with treatment. Anyone who develops osteomyelitis or who has been infected with penicillinase-producing bacteria is more likely to develop complications and problems that can delay recovery.

More research is needed in this area. This study is just the start but provides some unique and important insight into infectious arthritis among children. Physicians are now alerted that the hip and knee are not the only joints that can be affected by infections. The shoulder (though rare) is a potential target and should be considered as a possible diagnosis when children present with suspicious signs and symptoms of infection, fever, joint pain, and loss of arm or leg function.

Reference: Mohan V. Belthur, MD, et al. A Clinical Analysis of Shoulder and Hip Joint Infections in Children. In Journal of Pediatric Orthopaedics. October/November 2009. Vol. 29. No. 7. Pp. 828-833.