ABSTRACT: The best method for managing large bone defects during revision knee arthroplasty is unknown. Metaphyseal fixation using porous tantalum cones has been proposed for severe bone loss. Whether this approach achieves osseointegration with low complication rates is unclear.
We therefore asked: (1) What is the risk of infection in revision knee arthroplasty with large bone defects reconstructed with porous tantalum cones? (2) What is the rate of osseointegration with these cones? (3) What is the rate of loosening and reoperation? (4) Is knee function restored?
We retrospectively reviewed 27 patients who had 33 tantalum cones (nine femoral, 24 tibial) implanted during 27 revision knee arthroplasties. There were 14 women and 13 men with a mean age of 64.6 years. Preoperative diagnosis was reimplantation for infection in 13 knees, aseptic loosening in 10, and wear-osteolysis in four. Patients were evaluated clinically and radiographically using the score systems of the Knee Society and followed for a minimum of 2 years (mean, 3.3 years; range, 2-5.7 years).
One knee with two cones was removed for infection. All but one cone showed osseointegration. One knee was revised for femoral cone and component loosening. There was one reoperation for femoral shaft fracture and one for superficial dehiscence. The mean Knee Society pain score improved from 40 points preoperatively to 79 points postoperatively. The mean function score improved from 19 points to 47 points.
Our observations suggest metaphyseal fixation with tantalum cones can be achieved. Longer-term followup is required to determine whether the fixation is durable.
Clinical Orthopaedics and Related Research 04/2011; 470(1):199-204. · 2.53 Impact Factor
ABSTRACT: Management of a first-time anterior shoulder dislocation (FTASD) involves important clinical and policy decisions. Predictive disease modeling can improve the quality of information disseminated in treatment discussions. In this paper, we describe a general-purpose, publicly available model and illustrate its potential as a tool for management of a FTASD.
A Markov decision model of the natural history of a FTASD was constructed. Outcome probabilities and effectiveness were derived from the literature or estimated by expert opinion where necessary. Outcomes were the Western Ontario Shoulder Instability index (WOSI) and the probability of a patient experiencing recurrent instability, undergoing surgical stabilization, and having a stable shoulder at 10 years. The model was both internally and externally validated. Outcomes were examined for specific cases.
The model was effectively externally validated against two studies, a Swedish prospective cohort of Hovelius et al and Botonni et al's military cohort. It can produce detailed outcome predictions for individuals; eg, an 18-year-old man has a 77% risk of dislocation in year 1 and a 32% chance of having a stable shoulder in 10 years.
Detailed and specific information about prognosis is critical in the management of a FTASD. Disease modeling lends itself well to these needs and allows improved shared decision-making. Our model was externally validated and can predict specific outcomes. As a publically available resource, it will allow physicians to accurately predict the expected outcome of treatment based on covariates, patient demographics, and their own surgical success rates.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 03/2011; 20(2):259-66. · 1.93 Impact Factor
ABSTRACT: The long-term survival rate of total shoulder arthroplasty (TSA) is comparable to hip and knee arthroplasty. Although TSA is considered a safe and effective procedure with low complications in patients with osteoarthritis and rheumatoid arthritis (RA), data are lacking on perioperative complications. Complication rates and hospital disposition differences between patients with and without RA who underwent TSA were investigated. We hypothesized that RA patients would have poorer perioperative outcomes after TSA.
Data from the Nationwide Inpatient Sample was used to capture 25,398 patients between 1988 and 2005 who underwent TSA. Of these, 1,186 patients had a primary diagnosis of RA and were compared with 24,212 patients without RA. Analyses addressed perioperative complications and hospital disposition factors using bivariate and logistic regression models.
Overall complication rates were exceptionally low in both groups. Hospital disposition factors were significantly different between the 2 groups. The RA cohort had shorter average lengths of stay, higher likelihood of routine discharge, and lower inflation-adjusted cost before and after adjustment for covariates.
The occurrence of complications in the perioperative setting was less than 1% for both study groups in most variables investigated, and there were only minimal differences in perioperative complications between the groups. The significant differences in hospital disposition factors suggest that patients with RA may have less complex hospital stays and may be more comfortable being discharged under their own care. Recent studies describing the overall improvement in the management of patients with RA may also help explain these findings.
The findings suggest that the perioperative complications of a total shoulder replacement for patients with and without RA are similar. Contrary to our expectations, TSA patients with RA had shorter and less costly hospital stays and were more likely to have routine discharge. Complications are likely more long-term in nature than detected in this study and require longer follow-up beyond perioperative periods for fruition.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 01/2011; 20(1):77-85. · 1.93 Impact Factor
ABSTRACT: Periprosthetic joint infection in the acute setting is usually caused by gram-positive species and remains a major problem facing total joint surgeons. We report a case of a 53-year-old male who presented with drainage 3 weeks after primary total hip arthroplasty. Citrobacter koseri was cultured from an infected hematoma in his deep tissues. Surgical treatment included irrigation and debridement with femoral head and liner exchange. He received a 6-week course of ertapenem and is currently asymptomatic. We present C. koseri as a rare cause of acute periprosthetic infection and offer an effective treatment protocol.
The Journal of arthroplasty 12/2010; 26(6):978.e13-6. · 1.79 Impact Factor