| Osteoarthritis (OA) of the knee is one of the most | | | | doses were recommended. If the patients did not |
| common problems seen by both rheumatologists as | | | | improve within one month after completion of the |
| well as orthopedists in the office. The standard forms | | | | injections, they would be classified as a non-response |
| of therapy include maintenance of proper weight, | | | | group and total knee replacement surgery was |
| exercise, application of cold, bracing, analgesics (pain | | | | considered. Cost of direct medical costs (drugs), |
| killers), anti-inflammatory medicines, steroid injections, | | | | hospitalization, and resource utilization were recorded |
| and viscosupplementation. This latter type of | | | | and analyzed. |
| treatment involves the injection of a lubricant directly | | | | They concluded that IA-HA (joint injection with HA) |
| into the knee. | | | | should be considered as a medical intervention before |
| These lubricants consist of a purified form of a | | | | surgical procedures in knee OA patients who failed |
| protein called hyaluronic acid (HA). These preparations | | | | conservative treatments. Even though the cost of |
| are effective in relieving pain. pain relief from OA of | | | | IA-HA treatment would increase the total costs of |
| the knee starts between the 5th and 13th week | | | | treatment and some patients might fail, it was only |
| follwoing injection. While HA is felt to be effective for | | | | 6.44% of the total costs. On the other hand, if |
| pain relief, it has been unclear as to whether there | | | | patients responded to IA-HA treatment, then the |
| are any other benefits. | | | | surgical procedures were not required. This treatment |
| Two recent studies have demonstrated that | | | | would represent a savings of 63.26% of total costs. |
| viscosupplementation may actually forestall the need | | | | (Turajane T, et al. J Med Assoc Thailand. 2007; |
| for eventual knee replacement surgery and also may | | | | 90;1839). |
| represent a long term cost savings. | | | | While, the exact analyses and conclusions of these |
| The first study from Louisiana State University | | | | two studies are different, they do suggest that HA |
| surveyed patients from a large orthopedic practice. A | | | | may be cost effectve in delaying the need for total |
| total of 863 patients (1187 knees) were evaluated. All | | | | knee replacement. |
| patients had grade 4 changes, meaning they had | | | | There are five HA preparations available. They are |
| "bone on bone" and were candidates for total knee | | | | Hyalgan, Synvisc, Supartz, Orthovisc, and Euflexxa. |
| replacement. | | | | Only Euflexxa is not derived from a chicken source. |
| Using survival analysis of the data, it was estimated | | | | The number of injections required varies from 3-5 |
| that total knee replacement was delayed | | | | depending on the preparation used. Hyalgan and |
| approximately 3.8 years in 75 percent of the knees | | | | Supartz generally are given as weekly injections for 5 |
| receiving viscosupplementation (Waddell DD, et al. J. | | | | weeks while Synvisc, Orthovisc, and Euflexxa are |
| Managed Care Pharm. 2007; 2:113-121.) | | | | given as weekly injections for 3 weeks. |
| In another study, investigators in Thailand studied one | | | | Thes injections should be administered using either |
| hundred and eighty three patients with knee OA | | | | fluoroscopic or ultrasound needle guidance to ensure |
| (208 knees) who failed conservative treatments and | | | | accuracy. |
| did not have contraindications for surgery were | | | | Side-effects are minimal when administered by |
| enrolled. All patients were treated with one course of | | | | trained specialists. |
| three hyaluoronic acid injections at weekly intervals | | | | HA injections are worth a try even with grade 4 |
| and followed up for a minimum 2-year period. In case | | | | knees if patients wish to delay surgery. |
| of successful treatment (response group), repeated | | | | |