Matthew W. Tetreault

Corrosion at the Head-Neck Taper as a Cause for Adverse Local Tissue Reactions After Total Hip Arthroplasty

BACKGROUND Corrosion at the modular head-neck junction of the femoral component in total hip arthroplasty has been identified as a potential concern, although symptomatic adverse local tissue reactions secondary to corrosion have rarely been described. METHODS We retrospectively reviewed the records of ten patients with a metal-on-polyethylene total hip prosthesis, from three different manufacturers, who underwent revision surgery for corrosion at the modular head-neck junction. RESULTS All patients presented with pain or swelling around the hip, and two patients presented with recurrent instability. Serum cobalt levels were elevated prior to the revision arthroplasty and were typically more elevated than were serum chromium levels. Surgical findings included large soft-tissue masses and surrounding tissue damage with visible corrosion at the femoral head-neck junction; the two patients who presented with instability had severe damage to the hip abductor musculature. Pathology specimens consistently demonstrated areas of tissue necrosis. The patients were treated with debridement and a femoral head and liner exchange, with use of a ceramic femoral head with a titanium sleeve in eight cases. The mean Harris hip score improved from 58.1 points preoperatively to 89.7 points at a mean of 13.0 months after the revision surgery (p=0.01). Repeat serum cobalt levels, measured in six patients at a mean of 8.0 months following revision, decreased to a mean of 1.61 ng/mL, and chromium levels were similar to prerevision levels. One patient with moderate hip abductor muscle necrosis developed recurrent instability after revision and required a second revision arthroplasty. CONCLUSIONS Adverse local tissue reactions can occur in patients with a metal-on-polyethylene bearing secondary to corrosion at the modular femoral head-neck taper, and their presentation is similar to the adverse local tissue reactions seen in patients with a metal-on-metal bearing. Elevated serum metal levels, particularly a differential elevation of serum cobalt levels with respect to chromium levels, can be helpful in establishing this diagnosis.

Recurrent periprosthetic joint infection: persistent or new infection?

It is unclear if recurrent periprosthetic joint infection (PJI) is a result of failed pathogen eradication. This study addresses this issue. We identified 92 patients from three institutions who failed two-stage exchange. Cultured organisms at each stage of treatment were compared to determine whether these were persistent or new infections. Only twenty-nine of the 92 patients (31.5%) had identical organisms at treatment failure. Of the failures associated with Staphylococcus as the original infecting organism, 37% (25 of 67) failed due to the same organism compared to only 16% (four of 25) caused by other organisms. Positive cultures at reimplantation and poor health status were associated with higher rates of recurrent infection due to new organisms. Successful management of PJI with a two-stage exchange must stress minimization of comorbid risk factors that may contribute to the low success rate of PJI treatment and recurrence of infection.

Is Tommy John surgery performed more frequently in major league baseball pitchers from warm weather areas

Background: Medial ulnar collateral ligament (UCL) reconstruction is a common procedure performed on Major League Baseball (MLB) pitchers with symptomatic UCL insufficiency, frequently due to overuse. Warm weather climates afford youth pitchers the opportunity to throw year-round, potentially placing them at risk for overuse elbow injuries. Purpose/Hypothesis: To determine whether the proportion of MLB pitchers who underwent medial UCL reconstruction and who pitched competitive youth baseball in warm weather areas is higher than those from cold weather areas. The hypothesis was that MLB pitchers from warm weather areas were more likely to undergo UCL reconstruction than pitchers from cold weather areas. Study Design: Descriptive epidemiological study. Methods: All MLB pitchers with symptomatic UCL deficiency who underwent UCL reconstruction as of June 1, 2014, were evaluated. The state/country where they played high school baseball was identified from online reference websites. Warm and cold weather areas were defined by latitude distance from the equator and mean annual temperatures. A chi-square test was used to compare the proportion of MLB pitchers from warm versus cold weather areas who underwent UCL reconstruction. The study was 99.6% powered to detect a 100% effect size (eg, 1% vs 2%) and 71.4% powered to detect a 50% effect size (eg, 1% vs 1.5%) with setting α = .05. Results: A total of 247 pitchers were identified who had undergone UCL reconstruction; 139 (56.3%) pitched high school baseball in warm weather areas, 108 (43.7%) pitched in cold weather areas. A significantly higher proportion of pitchers who underwent UCL reconstruction (2.2% [95% CI, 1.9%-2.6%]) were from warm weather areas compared with cold weather areas (0.94% [95% CI, 0.78%-1.1%]) (P < .0001). Warm weather pitchers had a mean (±SD) age of 27.6 ± 0.6 years and had played 4.0 ± 0.6 seasons in MLB at the time of surgery, while cold weather pitchers were aged 28.4 ± 0.8 years and had played 5.0 ± 0.9 seasons in MLB (P = .089 and P = .047, respectively). Conclusion: MLB pitchers who played high school baseball in warm weather climates have undergone medial UCL reconstruction more frequently and earlier in their MLB careers than pitchers who played in cold weather areas.

Should Draining Wounds and Sinuses Associated With Hip and Knee Arthroplasties Be Cultured

We assessed the utility of culturing draining wounds or sinuses in evaluating periprosthetic joint infection (PJI). Fifty-five patients with a draining wound or sinus after total joint arthroplasty (28 knees, 27 hips) who had not received antibiotics for at least two weeks were prospectively studied. Superficial wound cultures were compared to intra-articular cultures to determine accuracy in isolating infecting organism(s). The superficial cultures were concordant with deep cultures in 26 of 55 cases (47.3%) and were more likely to generate polymicrobial results (27.3% vs. 10.9%; P=0.023). In 23 cases (41.8%), the superficial cultures would have led to a change in antibiotic regimen. Superficial cultures yielded bacterial growth in 8 of the 10 cases (80%) when deep cultures and further work-up suggested the absence of deep infection. Given the potential to misguide diagnosis and treatment, we recommend against obtainment of superficial cultures in patients with a draining wound or sinus following hip or knee arthroplasty.

Are Short Fully Coated Stems Adequate for “Simple” Femoral Revisions?

BackgroundMany studies suggest long femoral components should be used in revision THA. However, longer stems are more difficult to insert and reduce femoral bone stock for future revisions.Questions/purposesWe investigated (1) how frequently a short (≤ 160-mm or primary-length) fully porous-coated stem could be utilized for Paprosky Type I to IIIA femoral defects, (2) how often the tip of the old stem or cement mantle was bypassed by the revision implant, (3) Harris hip scores, radiographic signs of osseointegration, and revision frequency, and (4) complications associated with these reconstructions.MethodsTwo surgeons performed 277 femoral revisions graded as Paprosky Types I to IIIA between 2004 and 2009. When femoral canal diameter was less than 18 mm, these surgeons generally used the shortest stem capable of achieving a minimum of 4 cm of scratch fit in the femoral isthmus. Patients were evaluated clinically using the Harris hip score and radiographically for component loosening and to determine whether the revision component bypassed the prior stem tip or cement mantle.ResultsA short stem was utilized in 144 of the 277 revisions (52%). In 113 (78%), the revision femoral component did not bypass the tip of the prior stem or cement mantle. The Harris hip score improved (p < 0.001) from 36 preoperatively to 76 at a mean of 4 years (range, 2–8 years). Twelve stems required repeat revision including six (4.9%) for failed ingrowth. Complications included four intraoperative fractures, three postoperative femoral fractures, one cortical perforation, and eight dislocations.ConclusionsPrimary-length extensively coated stems provided reliable fixation for ½ of our Paprosky Type I to IIIA femoral revisions. When considering the use of such a component, the revision surgeon should take into account a small risk of failed osseointegration and technical challenges associated with this technique.Level of EvidenceLevel IV, therapeutic study. See the Instructions to Authors for a complete description of levels of evidence.

A cost comparison of unicompartmental and total knee arthroplasty

BACKGROUND Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty (TKA) in appropriately selected patients. There is a paucity of data comparing hospital resource utilization and costs for UKA versus TKA. METHODS We retrospectively reviewed 128 patients who underwent UKA or TKA for osteoarthritis by a single surgeon in the 2011 Fiscal Year. Sixty-four patients in each group were matched based on sex, age, race, body mass index, Charlson Comorbidity Index, and insurance type. Clinical data were obtained from medical records while costs were obtained from hospital billing. Bivariate analyses were used to compare outcomes. RESULTS Both anesthesia and operative time (minutes) were significantly shorter for patients undergoing UKA (125.7 vs. 156.4; p<0.001, and 81.4 vs. 112.2; p<0.001). UKA patients required fewer transfusions (0% vs. 11.0%; p=0.007) and had a shorter hospital stay (2.2 vs. 3.8days; p<0.001). 96% of UKAs were discharged home compared with 75% of TKAs (p<0.001). Hospital direct costs were lower for UKA (

Is There a Benefit to Modularity in ‘Simpler’ Femoral Revisions?

7893 vs.

What Factors Influence the Success of Medial Gastrocnemius Flaps in the Treatment of Infected TKAs

11,156; p<0.001) as were total costs (hospital direct costs plus overhead;

Same-day Discharge Compared with Inpatient Hospitalization Following Hip and Knee Arthroplasty

11,397 vs.

Sepsis Within 30 Days of Geriatric Hip Fracture Surgery

16,243; p<0.001). Supply costs and implant costs were similarly lower for UKA (