Commonsense design of patella implant: four years of clinical experience with 124 patients.

BACKGROUND: Patella resurfacing in Total knee Arthroplasty still is an issue of controversy, that results from the statistically poor performance of patella implants. Since the basic fault of conventional designs, in our opinion, is the inadequate thickness of the polyethylene, an innovative patella was designed and rules of technique were set to optimize the surgical procedure. METHODS: Since July 1998 we have employed the new patella in 124 consecutive patients undergoing total knee arthroplasty. They had the patella routinely resurfaced with an implant of a special design of a concave undersurface and a convex (dome) articulating surface. The thickness of the entire implant was uniform at all areas of contact. The bony patella was prepared with a concave reamer and shaped into a dome with a shallow central hole. Fixation with cement gave an optimally stable implant to shear forces and resistance to wear. RESULTS: All patients were studied prospectively and followed up to five years. Results were related specifically to performance of the patella as a part of the entire joint. Two patients died from unrelated causes. Four patients had delayed wound healing. One sustained a transverse fracture of the patella already healed with minimal displacement when she came to our attention. One sustained avulsion of the patella tendon from the tuberosity, which underwent surgical reattachment. Rest pain score (10-0) improved from 5.2 to 0.5. Activity pain score (10-0) improved from 9.0 to 1.4. Walking score (0-10) improved from 3.2 to 8.2. Stairs negotiation (0-10) improved from 2.8 to 8.0 and ADL Function (0-10) improved from 4.3 to 8.2. CONCLUSION: The special technique of resurfacing of the patella was developed during a short learning period. The new design of the patella implant, eight mm thick at any point of contact gave excellent and good results in 91%. There were no intra operative complications. During five years of follow up two complication were encountered and treated successfully: a minimally displaced transverse fracture and an avulsion of the patella tendon from the tuberosity. None of the patellae components required replacement. In our opinion the new design of bio-mechanically reliable patella implant will regain confidence of surgeons who presently refrain from patella resurfacing.

Hand infections following penetrating fish fins or bones injuries (FFBI): a large, hospital based, retrospective study.

BACKGROUND: The incidence of hand infections caused by penetrating fish fins or bones injuries (FFBI) is likely to increase following worldwide constant growth of fishery production and consumption. Because data on these infections are scarce, the purposes of this study were to describe their clinical characteristics and disease course, and to analyze risk factors for a complicated disease course. METHODS: We studied retrospectively all cases of hospitalized patients with hand infections following FFBI over the years 1999-2006 in a single medical center. Demographic data, underlying diseases, clinical characteristics and disease course were analyzed for each case. Univariate and multivariate analysis were used for analyzing risk factors for a complicated hospitalization course. RESULTS: There were 122 separate episodes of hand infections following FFBI among 116 patients, with a mean age (+/- SD) of 52 +/- 19.7. The majority of cases were women (51.6%), and they arrived significantly later to the hospital after injury. Predisposing conditions (diabetes mellitus, liver disease, rheumatologic disorder, malignancy or chronic steroid treatment) were present in 25% of cases. Most of the cases presented with cellulitis. Cultures of either blood or wound were obtained in approximately 1/3 of cases, and 40% of them yielded an isolate. Ceftazidime and doxycycline were administered to 68.8% and 96.7% of cases, respectively. Surgical debridement was performed in 34.4% of cases, but there was no case of death or limb amputation. The presence of fever (p = 0.0005) and a predisposing condition (p = 0.035) were independently correlated with a complicated hospitalization course. CONCLUSIONS: The overall prognosis in this largest cohort of hand infections following FFBI was favorable, but immune dysfunction carried a complicated course.