The requirements for a motion segment fusion for degenerative disc disease are relief from symptoms from a solid union with minimal damage to surrounding tissue. This is possible with the ‘Mini PLIF’ using the B Twin cages and facet screws. This procedure produces reliable relief of symptoms with a solid fusion. The use of facet screws mean that the nerve supply of the paraspinal muscles is protected. Between June 2002 and February 2006 35 patients underwent this procedure. There were 13 males and 22 females with an average age of 40 years from all walks of life. 30 patients had back and leg pain with only 5 having solely back pain. 28 patients had surgery at L5/ S1 with 4 patients at L4/5 and 3 at both. The median pre operation ODI was 53 (IQR 60–44) and at one year follow up the ODI was 24 (IQR 37–13). There were two complications of superficial infection and two pseudarthroses requiring pedicle screw constructs and revision bone grafting to achieve union. We believe this procedure demonstrates good relief from symptoms with a good fusion rate preserving the paraspinal muscles.
We have developed a novel, two-layered, collagen matrix seeded with chondrocytes for repair of articular cartilage. It consists of a dense collagen layer which is in contact with bone and a porous matrix to support the seeded chondrocytes. The matrices were implanted in rabbit femoral trochleas for up to 24 weeks. The control groups received either a matrix without cells or no implant. The best histological repair was seen with cell-seeded implants. The permeability and glycosaminoglycan content of both implant groups were nearly normal, but were significantly less in tissue from empty defects. The type-II collagen content of the seeded implants was normal. For unseeded implants it was 74.3% of the normal and for empty defects only 20%. The current treatments for articular injury often result in a fibrous repair which deteriorates with time. This bilayer implant allowed sustained hyaline-like repair of articular defects during the entire six-month period of observation.
