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Richard D Scott

Publications and source records attributed to Richard D Scott.

31 records · Page 2Linked to original sources
PubMed2004

The fate of patients not returning for follow-up five years after total knee arthroplasty.

BACKGROUND: Patients who do not return for follow-up after total knee arthroplasty are often assumed to have had a worse outcome. We postulated that the Internet may be useful for locating patients who do not return for follow-up. The purpose of this study was to compare outcomes between patients who attended prescribed postoperative appointments and those who did not. METHODS: We retrospectively reviewed the outcomes for 161 patients (200 knees) at a minimum of five years after a total knee replacement. All patients who had had no contact of any type with their surgeon in any manner beyond six months following the date of the surgery were classified as not having returned for follow-up. When patients could not be located with use of all available information in their chart, a standardized Internet search algorithm was employed with use of readily available and free search engines. RESULTS: Thirty patients with thirty-five treated knees met the definition of not returning for follow-up. Thirteen patients could not be located with use of the contact information given at their last visit. All were located with use of the Internet. None of the patients had had knee surgery elsewhere. The reasons for not adhering to the prescribed postoperative regimen were identified. The group had improved Knee Society pain and function scores compared with the preoperative values, and the patients were not significantly different from those who did return for follow-up. CONCLUSIONS: The patients who did not attend follow-up appointments in this series had not had any additional surgery and did not have any significant differences in measured outcome variables when compared with patients who had complied with a follow-up protocol. The Internet proved to be a valuable tool for locating patients who had not returned for follow-up postoperatively.

Adult↗
PubMed2003

Tibial plateau stress fracture: a complication of unicompartmental knee arthroplasty using 4 guide pinholes.

Unicompartmental knee arthroplasty has gained popularity recently as a treatment for unicompartmental tibiofemoral non inflammatory arthritis. Tibial plateau stress fracture after unicompartmental knee arthroplasty (UKA) through guide pin holes placed in the proximal tibia has not been previously reported. In each case in this report, the compressive strength of the proximal tibia was reduced by the drilling of multiple holes for the placement of guide pins and holes for the lugs of the tibia component resulting in fracture through these holes between 3 and 18 weeks (median 8 weeks) post-operatively. In at least one case, the medial tibial cortex was violated by one pin. All cases required revision total knee arthroplasty (TKA). It is intuitive to caution against the use of multiple guide holes in the proximal tibia in UKA. If 3 or more hole pins are deemed necessary, surgeons must be aware of the potential for stress fracture and monitor patients accordingly. Peripheral pins that infract the medial tibial cortex should also be avoided.

Aged↗
PubMed2003

UniSpacer: insufficient data to support its widespread use.

The concept of a UniSpacer is not new. McKeever and MacIntosh metallic hemiarthroplasties have been available for more than 50 years. Two decades ago, published reports for patients with unicompartmental OA revealed good initial results in 85% of patients. This procedure is conservative and easily revised, if necessary, to any type of arthroplasty in the future. The UniSpacer can be thought of as a mobile McKeever or MacIntosh metallic hemiarthroplasty. Rather than attempting fixation to the tibial plateau via a keel or a roughened undersurface, it is designed to translate freely on the tibial plateau as determined by the conforming articulation of its top side surface with the femoral condyle. This mobility makes it inappropriate for use in the lateral compartment where the femoral roll-back could cause prosthetic dislocation or soft tissue impingement or both. The eventual role of the UniSpacer in arthroplasty currently is uncertain. There are no published reports of its effectiveness. Its indication should be similar to those for McKeever arthroplasty. A patient with unicompartmental OA in whom an osteotomy is contraindicated but is considered too young, heavy, or active for a metal-to-plastic arthroplasty is ideal. Less than 1% of patients with OA should be appropriate candidates. The procedure is technically demanding and sensitive, making its widespread success unlikely.

Arthroplasty, Replacement, Knee↗
PubMed2003

Unicondylar arthroplasty: redefining itself.

Unicondylar knee arthroplasty is in the process of redefining itself. Increasing numbers of UKAs are being performed throughout the world, with some centers claiming that approximately 30% of their patients are candidates for this procedure. Because recovery from minimally invasive UKA can be rapid with a short or even overnight hospital stay, surgeons are broadening their indications for this procedure. I have concerns toward overuse of UKA. The procedure remains technically demanding and unforgiving. Conservative patient selection is advised and the fine points of the surgical technique should be learned through a moderately invasive patella-subluxing exposure before adapting minimally invasive techniques. The key to a rapid recovery following UKA is subluxing the patella rather than dislocating and everting the quadriceps mechanism. Unicompartmental knee arthroplasty is the right operation for the right patient when performed by the right surgeon using the right surgical technique.

Arthroplasty, Replacement, Knee↗
PubMed2002

Rheology of joint fluid in total knee arthroplasty patients.

While the properties of joint fluid may affect the tribology of joint replacement prostheses, the flow parameters of joint fluid have not yet been examined in the context of total knee arthroplasty (TKA). The objective of this study was to evaluate the flow properties of joint fluids in patients undergoing index TKA or revision TKA. We hypothesized that an alteration of the properties of joint fluid would result from TKA. The steady-shear viscosity and storage and loss moduli were evaluated in joint fluid from 35 arthritis patients undergoing TKA, 14 patients undergoing revision of a previous TKA, and two patients presenting with joint effusion after TKA. The same properties were also evaluated in two commercially available sodium hyaluronate preparations and bovine serum, which is used as a lubricant in joint simulators. The steady-shear viscosity varied over three orders of magnitude among samples obtained from patients undergoing TKA, spanning previously established "normal" and "diseased" ranges. Fluid obtained at index TKA was more likely to exhibit normal viscous properties than fluid obtained at revision TKA (p = 0.01). Other viscous parameters distinguished the two groups, but the difference did not reach statistical significance. Both groups exhibited degenerate flow properties when compared to synovial fluid from healthy individuals. Further examination of the connection between flow properties and the tribology of joint replacement prostheses is warranted.

Adult↗
PubMed2002

In vivo comparison of femorotibial contact positions for press-fit posterior stabilized and posterior cruciate-retaining total knee arthroplasties.

The objective of this study was to determine the in vivo medial and lateral femorotibial condyle contact positions for 20 subjects having either a posterior cruciate-retaining (PCR) or posterior-stabilized (PS) total knee arthroplasty (TKA) while sitting and kneeling. The two-dimensional radiographic images were converted into three-dimensional images using an iterative computer model-fitting technique. Anteroposterior contact positions, axial rotation, and condylar lift-off were assessed for each subject. In a seated position, the femorotibial contact points were, on average, posterior for both TKA groups (PCR: medial = -2.4 mm, lateral = -3.4 mm; PS: medial = -5.1 mm, lateral = -8.9 mm; medial, P=.21; lateral, P=.08). In a kneeling position, the contact position shifted anteriorly for the PCR TKA group (medial = 0.9 mm, lateral = -0.8 mm), whereas the contact positions in the PS TKA group remained posterior (medial = -5.6 mm, lateral = -8.3 mm; medial, P=.002; lateral, P=.0004). It is hypothesized that while in a kneeling position, the posterior cruciate ligament has less resistance to the anterior thrust of the femur relative to the tibia than in a PS TKA, in which this force is absorbed in the cam-and-post mechanism.

Arthroplasty, Replacement, Knee↗
PubMed2002

Unicompartmental knee arthroplasty for younger patients: an alternative view.

Unicompartmental knee arthroplasty has been a controversial operation for the past 3 decades. Many surgeons in the 1980s and 1990s found little or no indication for the procedure. Others were enthusiastic for its use in selected patients with osteoarthritis who had unicompartmental disease. Initially, unicompartmental knee arthroplasty was thought to be appropriate for the elderly patient who was sedentary. With the advent of minimally invasive techniques, indications have expanded to include its use in younger patients (especially females) as an alternative to osteotomy or tricompartmental knee arthroplasty. Advantages over osteotomy include higher initial success, greater longevity, and fewer early complications. If done conservatively, salvage is not difficult. The extent of safe postoperative activity levels has yet to be established. Failure rates seem to be higher in heavy active males. A metallic interposition hemiarthroplasty in the form of a McKeever or Macintosh prosthesis has been available for 50 years as a unicompartmental arthroplasty, but with limited use. It still may have a role in selected patients as a conservative temporizing procedure.

Adult↗
PubMed2002

Intraoperative measurements of male and female distal femurs during primary total knee arthroplasty.

The anteroposterior (AP) and medial-lateral (ML) dimensions of 200 consecutive osteoarthritic knees (100 males and 100 females) undergoing unilateral primary total knee arthroplasty were compared. For all patients, the mean AP dimension was 57.3 mm (range: 49-66 mm) and the dimension was 10.5% taller in height in men than women. The mean ML dimension was 71.6 mm (range: 56-85 mm), and the dimension was 13.7% wider in men than women. The mean AP/ML ratio was 0.8 for all patients, 0.82 (range: 0.73-0.93) for females and 0.79 (range: 0.70-0.89) for males (P<.001). The data suggest that for any given AP femoral dimension, women tend to have a narrower ML dimension than men, independent of AP height, and an AP/ML ratio of 0.80 most closely approximates a standard-sized distal femur across gender. This report documents important gender differences that may serve as a reference for femoral implant designers and knee surgeons.

Adult↗