U. Munzinger

The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, with intraclass correlation coefficients (ICC) higher than 0.86. The highest reliability was observed for concentric peak torque of the knee extensor muscles (ICC = 0.99). Test-retest reliability of fatigue variables was moderate for the knee extensor (ICC range 0.84-0.89) and insufficient-to-moderate for the knee flexor muscles (ICC range 0.78-0.81). The more reliable index of muscle fatigue was the linear slope of the decline in work output. These findings establish the reliability of isokinetic and isometric measurements using the Con-Trex machine.

INTRODUCTION: Patient's expectations are variably reported to influence self-rated outcome and satisfaction after medical treatment; this prospective study examined which of the following was the most important unique determinant of global outcome/satisfaction after total knee arthroplasty (TKA): baseline expectations; fulfillment of expectations; or current symptoms and function. METHODS: One hundred and twelve patients with osteoarthritis of the knee (age, 67 +/- 9 years) completed a questionnaire about their expectations regarding months until full recovery, pain, and limitations in everyday activities after TKA surgery. Two years postoperatively, they were asked what the reality was for each of these domains, and rated the global outcome and satisfaction with surgery. Multivariable regression analyses using forward conditional selection of variables (and controlling for age, gender, other joint problems) identified the most significant determinants of outcome. RESULTS: Patients significantly underestimated the time for full recovery (expected 4.7 +/- 2.8 months, recalled actual time, 6.1 +/- 3.7 months; P = 0.005). They were also overly optimistic about the likelihood of being pain-free (85% expected it, 43% were; P < 0.05) and of not being limited in usual activities (52% expected it, 20% were; P < 0.05). Global outcomes were 46.2% excellent, 41.3% good, 10.6% fair and 1.9% poor. In multivariable regression, expectations did not make a significant unique contribution to explaining the variance in outcome/satisfaction; together with other joint problems, knee pain and function at 2 years postoperation predicted global outcome, and knee pain at 2 years predicted satisfaction. CONCLUSIONS: In this group, preoperative expectations of TKA surgery were overly optimistic. The routine analysis of patient-orientated outcomes in practice should assist the surgeon to convey more realistic expectations to the patient during the preoperative consultation. In multivariable regression, expectations did not predict global outcome/satisfaction; the most important determinants were other joint problems and the patient's pain and functional status 2 years postoperatively.

BACKGROUND: There is a lack of detailed information concerning patients' sports and recreational activities after unicompartmental knee arthroplasty. HYPOTHESIS: Patients treated by unicompartmental knee arthroplasty will be able to return to sports and activity. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors surveyed 83 patients by postal questionnaires to determine their sporting and recreational activities at a mean follow-up of 18 +/- 4.6 months (range, 12-28) after unicompartmental knee arthroplasty. For data analysis, patients were divided into groups of women and men, and older and younger patients (those above and below the median age of the group). The authors also assessed the state of general health (SF-36) of the patients at the time of the survey and compared the results with those of a matched (for age and side-diagnoses) reference population. RESULTS: Before surgery, 77 of 83 patients were engaged in an average of 5.0 sports and recreational disciplines; postoperatively, 73 (88%) participated in an average of 3.1 different sports disciplines, resulting in a return to activity rate of 95%. The frequency of activities (sessions per week) was 2.9 preoperatively and remained constant at the time of survey (2.8). The group of older patients (mean age 73.0 y) revealed a significantly higher frequency than the group of younger patients (mean age 57.8 y). The minimum session length decreased from 66 minutes before surgery to 55 minutes after surgery. The most common activities after surgery were hiking, cycling, and swimming. Several high-impact activities, as well as the winter disciplines of downhill- and cross-country skiing had a significant decrease in participating patients. The majority of the patients (90.3%) stated that surgery had maintained or improved their ability to participate in sports or recreational activities. The patients generally scored very high on the SF-36 compared with the matched reference population. Higher SF-36 values in the physical-related domains correlated with an increased level of activity (r = 0.425). The preoperative body mass index showed a weak, negative correlation with the postoperative extent of activities (r = -0.282). CONCLUSION: The majority of patients returned to sports and recreational activity after unicompartmental knee arthroplasty. However, the numbers of different disciplines patients were engaged in decreased as well as the extent of activities. The activities in which most patients participated were primarily low- or midimpact. The patients scored higher on the SF-36 than age-related norms, which might be due to the patient-selection process for unicompartmental knee arthroplasty and geographical differences.

Hip arthroscopy is being recognized as a valuable additional procedure in the treatment of disorders of this joint. Although initially employed as a diagnostic tool only, better understanding of the anatomy involved and advanced skills have now made surgical treatment possible. Because the techniques are still evolving, a standardized approach is just being established. Little is known on possible complications associated with the procedure, concentrating in most cases on the neurovascular structures at risk during instrument introduction. This study reports on 19 patients in whom three complications were encountered. Two were attributable to positioning problems of the patients, and one was caused by intraoperative extravasation of irrigation fluids. The available literature on complications in hip arthroscopy is being reviewed, and the prevention of complications as experienced in this series is being discussed.