Does minimal-incision surgery lead to early failure of THA?
Findings from a new study suggest that minimal-incision total hip arthroplasty (MI THA) could put patients at risk for early revision surgery. Moreover, long-term survival after MI THA may be lower than that for patients who undergo non-MI surgery.
Researchers conducted a retrospective review of 46 revision THAs done during a 3-year period. They excluded revisions performed for infection and re-revisions. Patients with incisions 10 cm or smaller were defined as having undergone MI THA. Fifteen of the 46 patients (33%) were thus defined as having undergone primary MI THA. At the time of primary THA, the average patient age was 65 years in the MI group and 55 years in the non-MI group.
For patients who underwent MI THA, the average time to revision was 1.4 years, compared with 14.7 years for patients in the non-MI group. Twelve of the 15 patients who underwent MI THA required revision within 2 years of primary THA, compared with four of the 31 patients who didn't have MI surgery (odds ratio, 26.5; 95% confidence interval, 4.4-160.0). There were no significant differences between the two groups in age, sex, or body mass index. The most common reasons for revision in the MI THA group were intraoperative fracture and failure of femoral component osseointegration.
Source: Graw BP, Woolson ST, Huddleston HG, Goodman SB, Huddleston JI. Minimal incision surgery as a risk factor for early failure of total hip arthroplasty. Clin Orthop Relat Res. 2010 Mar 30. [Epub ahead of print]
How ankle taping benefits biomechanics during sports
A new study analyzes the benefits and drawbacks of ankle taping. Ankle taping limits the ankle's range of motion and increases its mechanical stability. It also protects the knee by allowing fewer moments of internal rotation, and it reduces varus impulse during planned and unplanned movement. However, ankle taping seems to contribute to medial collateral and anterior cruciate ligament injuries via increased valgus impulse during sidestepping.
In the study, researchers used a kinematic and inverse dynamics model to determine ankle and knee joint motion and loading in 22 healthy men. The subjects ran and performed sidestepping motions. Both tasks were randomized to planned and unplanned conditions, and they were performed with and without the ankle taped.
At the knee, ankle taping reduced internal rotation moments and varus moments during all tasks. Internal rotation impulse was reduced during sidestepping tasks. Varus impulse during unplanned sidestepping maneuvers was also reduced with ankle taping.
However, there was a trend toward increased valgus moments and impulse for planned sidestepping trials completed with the ankle taped (p=0.056). Taping reduced the range of motion at the ankle in all three planes (p<0.05). Peak inversion (p<0.001) was reduced only during running trials. Taping significantly reduced average eversion and peak dorsiflexion moments during sidestepping tasks.
Source: Stoffel KK, Nicholls RL, Winata AR, Dempsey AR, Boyle JJ, Lloyd DG. The effect of ankle taping on knee and ankle joint biomechanics in sporting tasks. Med Sci Sports Exerc. 2010 Mar 25. [Epub ahead of print]
Much ado about tallying surgical-site infections
Should national standards for reporting surgical-site infections (SSIs) distinguish between primary and revision orthopaedic surgeries? To answer that question, researchers compared the SSI rate after primary total hip arthroplasty (THA) with the SSI rate after revision THA.
The investigators obtained THA data from an institutional, prospectively maintained surgical database. For SSIs, they reviewed prospectively collected data, used for routine infection control surveillance, in accordance with Centers for Disease Control and Prevention criteria for the definition of an SSI. Researchers used logistic regression analyses to evaluate differences between the SSI rates after primary THA and after revision THA.
The investigators analyzed 5696 THAs (with type 1 wound classification), of which 1381 (24%) were revisions. A total of 61 SSIs occurred, resulting in an overall SSI rate of 1.1% for all THAs. When stratified according to the National Nosocomial Infection Surveillance (NNIS) risk index, SSI rates were 0.5%, 1.2%, and 1.6% in risk categories 0, 1, and 2, respectively.
After controlling for the NNIS risk index, the risk of SSI after revision surgery was twice as high as that after primary THA (odds ratio, 2.2; 95% confidence interval, 1.3-3.7). In an analysis restricted to the development of deep incisional or organ-space infections, the risk of SSI after revision THA was nearly 4 times the risk after primary THA (odds ratio, 3.9; 95% confidence interval, 2.0-7.6).
The researchers concluded that differences between primary and revision surgeries should be considered in national standards for reporting SSIs. Inclusion of revision surgeries in the calculation of SSI rates can produce higher infection rates for facilities that perform a greater number of revisions. Taking NNIS risk indices into account does not eliminate this effect.
Source: Leekha S, Sampathkumar P, Berry DJ, Thompson RL. Should national standards for reporting surgical site infections distinguish between primary and revision orthopedic surgeries? Infect Control Hosp Epidemiol. 2010 Mar 29. [Epub ahead of print]
Gender gap after arthroscopic shoulder stabilization?
Compared with men, women have decreased shoulder function and stability after arthroscopic shoulder stabilization. In a study involving 24 men (average age, 30 years) and 12 women (average age, 32 years), three of the women (25%) had a positive sulcus sign test, which indicates increased joint laxity. Just three of the 24 men (12.5%) had the same result, although these findings fall short of statistical significance (p=0.378).
Patients underwent arthroscopic shoulder stabilization for anterior shoulder instability after traumatic shoulder dislocation. After surgery, patients were examined by orthopaedic physicians where their Constant-Murley score was raised, and apprehension and sulcus sign tests were conducted. At almost 5 years of follow-up, women had significantly decreased Constant-Murley scores compared with men (p=0.045). A positive apprehension test, indicating decreased shoulder stability, was also found more often in women than in men (p=0.018).
Source: Kaipel M, Reichetseder J, Schuetzenberger S, Hertz H, Majewski M. Sex-related outcome differences after arthroscopic shoulder stabilization. Orthopedics. 2010 Mar 1:163-167. [Epub ahead of print]
Evaluating an alternate drug plan for patients with RA
Using a low-dose combination of oxycodone and acetaminophen to treat chronic pain in patients with rheumatoid arthritis (RA) can be a good alternative to nonsteroidal anti-inflammatory drugs (NSAIDs), researchers have found. The drug combination permits reduced NSAID consumption while RA therapy remains stable, researchers concluded.
The study included 29 patients with RA who experienced moderate to severe pain for more than 3 months. None of the study participants was taking biological drugs. Treatments started with oxycodone/acetaminophen at a dosage of 5 mg/325 mg. Dosages were titrated until patients achieved good pain relief. Patents received antiemetic and laxative therapy for prophylaxis of known opioid-related adverse events.
Patients continued their standard RA therapy without a change in dosage. They reported reductions in pain intensity and disease activity and improvement of disability. Forty-two percent of patients had a good clinical response to oxycodone/acetaminophen treatment, according to assessment criteria from the European League against Rheumatism (EULAR). Additionally, 50% of patients reached American College of Rheumatology 20% improvement criteria (ACR20).
At the conclusion of the study, the average daily effective oxycodone/acetaminophen dose was 13.8 mg/720.4 mg. No serious adverse events were observed. Nausea, vomiting, and constipation of mild to moderate intensity were the most common adverse events.
Source: Raffaeli W, Pari C, Corvetta A, et al. Oxycodone/acetaminophen at low dosage: an alternative pain treatment for patients with rheumatoid arthritis. J Opioid Manag. 2010 Jan-Feb;6(1):40-6.
Physicians and patients: expectation realignment needed
Before replacing another knee or hip joint, consider having a frank discussion with the patient to ensure you have similar postoperative expectations. Too often, patients and physicians have different expectations regarding surgical outcomes, according to new study results reported by researchers from the Hospital for Special Surgery (HSS), in New York City, at the annual meeting of the American Academy of Orthopaedic Surgeons, held March 9-13 in New Orleans (poster P140).
In a study that used surveys to compare expectations of 42 patients with those of their physicians, investigators found that 68% of patients had clinically meaningful disagreements with their physicians. Fifty-three percent of patients' expectations exceeded the expectations of their surgeons.
The study included 25 patients who were scheduled to undergo total hip replacement (THR) and 17 who were scheduled for total knee replacement (TKR) to be performed by a dedicated hip and knee surgeon. Patients and physicians completed either a THR or a TKR recovery expectation questionnaire. The surveys involved fewer than 20 questions regarding expected improvement in psychological well-being, pain relief, and various aspects of physical functioning and ability. Respondents answered the questions using a 5-point scale. A score of 1 indicated an expectation of "return to normal;" 4, "very little improvement;" and 5, "I don't have this expectation."
Scores were then calculated to range from 0 to 100, with 100 being the highest expectation for improvement. The average surgeon expectation score was 75 (range, 43-93) and the average patient expectation score was 84 (range, 47-100).
"The take home message for the surgeon is that inexpensive, educational interventions like a preoperative class can be used to better align the patient's and the surgeon's expectations prior to surgery," said Alejandro Gonzalez Della Valle, MD, associate attending orthopaedic surgeon at HSS, who was involved with the study. "This may ultimately result in higher perceived outcome."
"If a patient has unrealistic expectations that are not properly trimmed preoperatively or achieved after surgery, the patient will most likely be dissatisfied with some aspects of the final result. Conversely, if the patient has low expectations for function after surgery, it is likely that he or she will not enthusiastically engage in the different phases of the postoperative recovery, including physical therapy. That patient will probably have a lower than expected functional result," said Dr. Gonzalez Della Valle.
The verdict on 4-hour clamping drainage after TKA
No wound drainage may be better than 4-hour clamping drainage after total knee arthroplasty (TKA), new study findings suggest. The role of wound drainage in TKA is controversial. Drainage has been thought to help reduce the risk of hematoma formation, but typically it increases bleeding because it eliminates the tamponade effect of a closed and undrained wound. Clamping the drain tube for the first 4 hours after TKA can create a temporary tamponade effect that helps control bleeding.
Researchers conducted a study to compare outcomes in patients with temporarily clamped drains and without drains. One hundred consecutive patients undergoing primary TKA were included in the study. The investigators recorded changes in hemoglobin levels, blood transfusion needs, use of narcotics, use of postoperative wound dressings, length of hospital stay, and range of motion.
Patients in the drain-clamping group had greater postoperative hemoglobin loss and longer hospital stays, and they gained no benefits compared with patients in the group without drains. Researchers concluded that despite clamping for 4 hours after TKA, the drain was of no use. Given their findings, they do not recommend routine use of a draining system after TKA.
Source: Tai TW, Jou IM, Chang CW, Lai KA, Lin CJ, Yang CY. Non-drainage is better than 4-hour clamping drainage in total knee arthroplasty. Orthopedics. 2010 Mar 1:156-160. [Epub ahead of print]
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