Purpose: surgical fixation distal femoral fractures has been associated withnonunion and varus collapse. the soft tissue stripping esulted from this fracture and caused by the surgical approach have been factorassociated with delayed union and infection. the limited soft tissue exposure has been lauded as a solution to this fracture. however, it has occurred with new fixation as well (locked plate) this study is an attempt to look at the fixation from the surgical approach prospective. does the liss system improve the results of this difficult fracture? is there truly a difference in the outcome of this fracture utilizing the locked plate system or the percieved difference due to surgical mini invasive approach.

Method: one hundred and forty patientswere screened, and only 53 were randomized and treated in six academic centers over five years. all c3 fractures were excluded from the study as they were felt not to be treatable by the dcs device, but they were treated and fixed appropiately. thirty five females and 18 males were included and appropiately randomized.

Results: fifty three patients were randomized, 28 had the liss implant while 25 had the dcs utilized. there were three nonunions in the liss group, plus two patients required an early reoperation in the early post operative periods ( second – fifth post op. day) due to an early loss of reduction. further more, one patient developed a knee arthrofibrosis that required arthroscopic joint release with subsequent implant failure. that necessiated a reoperation. in the dcs group there was only one nonunion, that required reoperation. this translated into reoperation rate of 21%in the liss group compared to 4% with dcs.

Conclusion: this prospective multicenter randomized trial showeda significant difference when comparing the liss device to the dcs system in minimal invasive approach of distal femoral fractures fixation

Purpose: Proximal humeral fractures are a commonplace injury, especially in the elderly population. Management is not always straightforward, and is particularly challenging when bone quality is poor. In recent years, locking plates have become available for the internal fixation of many types of fractures, including those of the proximal humerus, and a growing trend in their use has been noted. This is a randomized biomechanical study to evaluate the mechanical stability in simulated osteoporotic bone of three fixation plates, two locking and one conventional, for unstable two-part proximal humeral fractures.

Method: Eighteen synthetic left humeri were plated with six bones in each of three groups: Synthes Cloverleaf Plate, Synthes Locked Compression Plate Proximal Humerus, and Smith and Nephew Periarticular Locking Plate for Proximal Humerus. Screw holes were overdrilled to simulate osteoporotic purchase. The distal humeral condyles were potted in autobody cement in polyvinylchloride tubes. An eight millimeter osteotomy gap was made at the base of the greater tuberosity to simulate an unstable two-part fracture. Cyclic axial compression testing was done in the vertical plane in 20 degrees of abduction to simulate physiologic loading. Measurements of plastic deformation of the construct were quantified by comparing RSA images taken before and after loading. Following cyclic axial compression testing, quasi-static torsion testing was done in the horizontal plane until construct failure. Failure was defined as the point where the linearity of a load-displacement curve is lost or where visible failure of the fixation occurs.

Results: No plates were loaded to failure. The locked plates were significantly stiffer in axial compression and torsion than the Cloverleaf plate. There was no difference between locked plates. The maximum total point motion seen on the RSA analysis was more than 4 times greater in the Cloverleaf group relative to either locked construct and no difference between the Synthes and Smith and Nephew locked plates was again seen. The majority of the motion in the Cloverleaf construct appeared to be in rotation about the anteroposterior axis (lateral rotation).

Conclusion: This study supports that locked plates, regardless of manufacturer, are stiffer in axial compression and torsion than Cloverleaf plates and result in less displacement in an unstable fracture pattern in an osteoporotic bone model.

Purpose: The ideal bearing surface for total hip arthroplasty is still an area of debate. Increasing numbers of total hip replacements are being done in the younger patient population. Ceramic-on-ceramic bearings have gained popularity due to their low wear rate; however, ceramic fractures with subsequent catastrophic failures have been reported and squeaking of ceramic hips is an emerging problem. This study reports on early results of ceramic-on-ceramic total hip replacements.

Method: This is a study analyzing prospectively collected data for 120 alumina-on-alumina total hip replacements with minimum follow up of 24 months. Average age at time of surgery was 49 years. The main outcome of the study was to identify complications related to the pros-theses. Standard outcome measures (SF-12, Harris Hip Score, and WOMAC) were also collected at clinic visits.

Results: All patients received either a Stryker Trident acetabular cup with Secure-fit Plus stem or Depuy Pinnacle cup with an AML stem. Average follow-up was five years (range: two – nine years). No revisions were performed for loosening or catastrophic failures. No wear, loosening, or osteolysis was seen on radiographs. The SF-12, WOMAC, and Harris Hip scores were not significantly different from other reported hip series. The most common complication has been the “squeaking” hip. To date we have had six squeaky hips in our centre, three of which have been revised. All the squeaking hips received the Trident acetabular cup (Stryker) which has a circumferential metal lip to protect the ceramic bearing. This metal flange can affect range of motion and predispose patients to earlier impingement (particularly if a minus 3 head is utilized). One patient with a Depuy hip complains of intermittent pain and radiographs show some fragmentation, but the hip has not been revised.

Conclusion: Ceramic-on-ceramic bearing surfaces in total hip arthroplasty may provide a more durable prosthesis with outcomes similar to standard THA, especially in young and active patients; however, caution should be used if considering the Stryker Trident shell due to the large number of “squeaky hips”.

One hundred and ninety patients requiring total knee arthroplasty were randomized to one of two treatments: retaining or sacrificing the posterior cruciate ligament during surgery. Both groups received a Genesis II implant (Smith and Nephew Richards) appropriate to the treatment. Patients were seen preoperatively, at three months, one year, and two years. The end-of-study date is at five years postoperatively. Outcome measures include range of motion, the KSCRS, SF-12, and WOMAC. At two years both groups have shown improvement in pain, function, and stiffness. There is no apparent difference between groups with regard to any outcome measures or complications.

The purpose of this study was to compare retaining vs. sacrificing the posterior cruciate ligament (PCL) in total knee arthroplasty in the patients who satisfy the criteria for a cruciate retaining knee.

Two years after total knee replacement, both groups have improved knee function, less pain, and less knee stiffness. There is no apparent difference between the groups with regards to range of motion, function, or other outcome measures.

Designs of total knee arthoplasty implants, as well as surgical techniques continue to evolve. The role of the PCL in primary total knee arthroplasty remains controversial. Current prosthetic designs have the flexibility to either substitute for a resected PCL or allow preservation of the ligament.

One hundred and ninety patients requiring total knee arthroplasty upon satisfying the criteria for a cruciate retaing arthroplasty were randomized to receive either a posterior cruciate retaining implant or a posterior cruciate sacrificing implant. Surgery was performed following standard procedure with the only difference between groups being the sacrificing or retaining of the PCL. Patients were followed at three months, one year, and two years postoperatively. Outcome measures included range of motion, the Knee Society Clinical Rating Score (KSCRS), SF-12, and Western Ontario and McMaster Osteoarthritis Index (WOMAC).

Early results indicate that both groups are doing equally well with no statistical difference in outcomes at two years. There is a trend toward increased range of motion at six and twelve months in the PCL sacrificing group. A six- degree gain was noted in the sacrificed group as compared to a two degree gain in the intact group.

Funding: Smith and Nephew