Abstract
BackgroundFor focal cartilage defects, biological repair might be ineffective in patients over 45 years. A focal metallic implant (FMI) (Hemi-CAP Arthrosurface Inc., Franklin, MA, USA) was designed to reduce symptoms. The aim of this study was to evaluate the effects of a FMI on the opposing tibial cartilage in a biomechanical set-up. It is hypothesized that a FMI would not damage the opposing cartilage under physiological loading conditions.MethodsAn abrasion machine was used to test the effects of cyclic loading on osteochondral plugs. The machine applied a compressive load of 33 N and sheared the samples 10 mm in the anteroposterior direction by 1 Hz. Tibial osteochondral plugs from porcine knees were placed in opposition to a FMI and cycled for 1 or 6 h. After testing each plug was fixed, stained and evaluated for cartilage damage.ResultsAfter 1 h of loading (n = 6), none of the osteochondral plugs showed histologic signs of degradation. After 6 h of loading (n = 6) three samples had histologic signs of injury in the tangential zone (grade 1) and one had signs of injury in the transitional and deep zones (grade 2). Exploration for 6 h resulted in significant more cartilage damage compared to the shorter exploration time (p = 0.06). However, no significant difference between saline and hyaluronic acid was evident (p = 0.55).ConclusionUnder physiologic loading conditions, contact with a FMI leads to cartilage damage in the opposing articular cartilage in six hours. In clinical practice, a thorough analysis of pre-existing defects on the opposing cartilage is recommended when FMI is considered.
Highlights
For focal cartilage defects, biological repair might be ineffective in patients over 45 years
Biologic treatment options directly addressing focal cartilage defects do not provide the same benefit seen in younger patients, while the more aggressive total knee arthroplasty (TKA) is generally reserved for severe symptomatic osteoarthritis in older patients
After 6 h, signs of cartilage damage were present in one of three specimens tested in saline, and in two of three specimens tested in hyaluronic acid (Fig. 3)
Summary
Biological repair might be ineffective in patients over 45 years. A focal metallic implant (FMI) (Hemi-CAP Arthrosurface Inc., Franklin, MA, USA) was designed to reduce symptoms. Biologic treatment options directly addressing focal cartilage defects do not provide the same benefit seen in younger patients, while the more aggressive TKA is generally reserved for severe symptomatic osteoarthritis in older patients. A focal metallic implant (FMI) (Hemi-CAP Arthrosurface Inc., Franklin, MA, USA) was developed as a midway point for such patients to treat symptomatic focal cartilage defects and prevent progression of OA. A protruded implant may be a clear etiology of damage to opposing cartilage, some animal studies reported defects in the setting of a flat implant [4, 5, 24]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
