The acute effects of graded physiological strain on soccer kicking performance: a randomized, controlled cross-over study.

PURPOSE: The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance. METHODS: Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones. RESULTS: Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p < 0.05), KV (3-4%; p < 0.05), and overall KQ (13-15%; p < 0.01). The light and moderate-intensity exercise below the LT2 had no significant effect on soccer kicking performance. CONCLUSIONS: The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.

Functional recovery after muscle sparing total hip arthroplasty in comparison to classic lateral approach - A three years follow-up study.

BACKGROUND: The muscle sparing total hip arthroplasty had generated a distinguishable interest, in both the patients and the surgeons, but its benefits are still often questioned. The main idea of this study was to compare the functional clinical outcome of the patients operated by the anterolateral approach with a muscle-sparing technique (modified Watson-Jones approach), and the patients operated by modified direct lateral approach without the muscle-sparing technique (Bauer/Hardinge approach). METHODS: The patients (N = 130) were divided into two groups: 68 in a standard method group (STAND) and 62 patients in a muscle sparing surgery group (MSS). The hip flexibility, mobility, the strength of the hip abduction, the pain scale, Harris hip scores, the duration of the hospital stay and the overall satisfaction were measured seven days, three months, one year and three years (in 80 patients) after the surgery. There were no differences in any of the parameters between the groups prior to the procedure. RESULTS: The statistically significant differences in first three follow-ups (up to one year) were determined between the groups in passive and active hip flexion ability but the hip abduction strength, which is a crucial parameter for functional recovery, and 50 m walk test remained better in MSS group even after three years. Patients, who underwent MSS suffered also less pain, stayed in hospital shorter and were more satisfied with the operation outcome. CONCLUSIONS: The functional recovery in patients treated with muscle sparing method was faster than in patients operated with conventional lateral approach. Based on the results, we could recommend anterolateral muscle sparing approach for a total hip replacement for its faster and fuller functional recovery.

Ultrasound-assisted calcaneoplasty.

PURPOSE: The endoscopic technique for resection of a postero-superior part of calcaneus served as a golden standard during the last 10 years, and it has mostly replaced the open techniques. In an effort to reduce the morbidity and the recovery time, we had introduced the ultrasound-assisted technique. METHODS: In the period of 1 year, 15 patients with the prominent postero-superior part of calcaneus and retrocalcaneal bursitis were operated through the single skin incision using the ultrasound-assisted technique. The prominent part of calcaneus was resected with a bone abrader under the ultrasound control to the point when there was no impingement between Achilles tendon and calcaneus in maximal dorsal flexion. The patients were evaluated preoperatively and postoperatively with the AOFAS score and Ogilvie-Harris score. The strength test of the muscle triceps surae, as well as the proprioceptive test, was also undertaken. RESULTS: Initially, the follow-up was meant to last 6 months, but there were no differences in results between 6 weeks and 3 months postoperatively, so it was concluded that the 3-month follow-up is sufficient and relevant. All 15 patients were available for follow-up. All measured variables significantly improved (AOFAS, Ogilvie-Harris), and all the patients were satisfied with the postoperative result. Only one minor complication occurred: superficial infection. CONCLUSION: The ultrasound-assisted calcaneoplasty enables a precise resection of the postero-superior part of calcaneus and removal of the retrocalcaneal impingement. This method could become clinically relevant as it enables effective treatment of Haglund deformity, and results of this study presented rapid functional recovery. LEVEL OF EVIDENCE: Case series with no comparison group, Level IV.

Postoperative blood loss management in total knee arthroplasty: a comparison of four different methods.

PURPOSE: As the blood loss after the total knee arthroplasty (TKA) is not only a potentially serious medical problem but also an economical concern, the purpose of the study was to investigate the effectiveness of different combinations of knee positioning and the applied wound dressings on blood saving after TKA. METHODS: A randomized controlled trial including 147 TKA-operated patients was conducted. The subjects were assigned to one of the four groups; Group 1-controls, Group 2-flexion, Group 3-flexion and compression, Group 4-compression. The main outcome measures of the study were the blood loss volumes during the procedure and in the intensive care rooms and the decreases in haemoglobin, haemotocrit and red blood cells on the first and the second postoperative day. RESULTS: The MANOVA results showed no differences between the groups in any of the observed parameters. The post-hoc comparisons of the each group to the control group also revealed no influence of any of the proposed blood saving techniques on the actual blood loss. CONCLUSION: No significant differences among the four proposed blood saving methods were determined.

New "L value" parameter simplifies and enhances hip ultrasound interpretation in the detection of developmental dysplasia of the hip.

PURPOSE: The purpose of this study was to simplify and enhance the ultrasound (US) analysis of the infant's hip by introducing a novel parameter named "L value" into the widely used Graf method. METHODS: We analysed 508 ultrasonographic images of the hips in infants aged three months. The images were first evaluated using the Graf measurements. On the same images, two additional measurements were performed in order to define the new parameter that was named L value. The threshold values of the new L value were identified based on the highest specificity as well as sensitivity for discrimination between the Graf groups. Those values were then used in order to reclassify the hips into three simplified groups. Inter-observer agreement was estimated by Cohen's kappa coefficient. RESULTS: The threshold values for the L value between Graf groups Ia and Ib was 0.46, between Ib and IIb was 0.68 and between IIb and IIc was 0.92. Correlation analysis between Graf's classification and the values of the L value was performed and was proved to be statistically significant, r = 0.49; p < 0.001. After simplifying the classification into three newly defined groups of patients depending on the degree of hip development, the correlation coefficient was much higher, r = 0.94, r (2) = 0.88 for p < 0.001. Inter-observer agreement for the L value was substantial. CONCLUSIONS: The new L value parameter in Graf's ultrasound hip evaluation enables a faster, simpler, more reliable and more unbiased classification for developmental dysplasia of the hip as the L value changes proportionally with the hip maturity.

The influence of test repetition on bipodal visually controlled static and dynamic balance.

This study explores the influence of test repetition on bipodal visually controlled balance, both static and dynamic. Our goal was to get an insight into the pattern of changes in posture maintenance results during repeated balance tests. Fifteen young, healthy male recreational athletes were tested for static and for dynamic balance using KAT 2000 balance platform. The subjects first performed three trial tests of static and dynamic balance to get used to the platform followed by seven repetitions of static as well as dynamic test which were recorded. During the repeated tests we could not determine any significant improvements of static balance test resulting from number of test repetitions neither in static nor in dynamic balance (Friedman ANOVA: Static balance p = 0.497, Dynamic balance p = 0.393). Correlating static and dynamic balance results we found that only one third of the dynamic balance was related to static balance abilities (r2 = 0.36). Possible patterns in front-back and left-right directions were analyzed as well, however, none of these balance scores were found to be related to the number of repetitions. In conclusion, this study found no significant influence of limited number of repetitions (seven) on test results in static and dynamic posture. However, as large number of repetitions might still influence test results we discourage the use of KAT 2000 as a training tool in patients in which it will be used as an instrument to validate postoperative rehabilitation or investigation results.

A new tibial torsiometer applicable to clinical practice.

This study evaluated a new tibial torsiometer that is universally applicable to all limb sizes and requires no special training, jigs, or radiographic equipment. To compare the reliability of measurements obtained with the torsiometer, 160 tibias were evaluated with both the torsiometer and computed tomography. Results for both methods were identical in 51 tibias, within 1 degrees in 66 tibias, and within 2 degrees in 43 tibias. The difference between the two methods was not significantly different. No significant differences were found among examiners. This device should prove to be useful for the quantification of tibial torsion.

Microfracture technique in combination with intraarticular hyaluronic acid injection in articular cartilage defect regeneration in rabbit model.

Although articular hyaline cartilage typically has low potential for regeneration, numerous methods and techniques have been proposed to induce the reparation process. In our work, we used microfracture techniques in combination with intraarticular application of hyaluronic acid in rabbit knee articular cartilage defect. In comparison with the control group, after 6 and 10 weeks we observed a higher potential of healing in the experimental group, with thicker and more organized repair tissue filling the defect. In conclusion, a combination of the microfracture technique and application of hyaluronic acid might be potentially beneficial in inducing articular cartilage defect reparation.

Synovial chondromatosis of the pisotriquetral joint with secondary osteoarthritis: case report.

There are only a few reported cases of synovial chondromatosis affecting pisotriquetral joint (PT). Osteoarthritis of the PT is also rare and can be as disabling as osteoarthritis of any other joint. We report this to be the unique case of synovial chondromatosis of the PT joint with secondary osteoarthritis.

The rational strategies for detecting developmental dysplasia of the hip at the age of 4-6 months old infants: a prospective study.

Using ultrasound in evaluation of infant's hip development can reduce surgical procedures, hospitalization and late presentation of developmental dysplasia of the hip (DDH). The increasing incidence of DDH after ultrasound examination is observed and published by many authors. In a prospective study, radiograph of every single ultrasonographic positive hip in infants older than three months, was taken and analyzed in order to see whether it affects infants splintage rate in treating DDH. In a period of 30 months, clinical and simple static ultrasonographic examinations according to Graf were performed on 1430 consecutive infant hips in patients aged between 4 and 6 months. Sonographic positive hips were radiographed and acetabular index (AI) values on simple AP radiographs were analyzed. The sonographic DDH incidence was 51.75 per 1000 hips (51.75 per thousand). After X-ray examination of all 74 ultrasonographic positive hips, only 44 remained abnormal and required treatment indicating a true DDH incidence of 30.77 per 1000 hips (30.77 per thousand). The difference in incidence per ultrasonographic and X-ray positive hips is statistically significant p < 0.01 (t = 5,536). The rational approach in detection of DDH in a child more than 3 months old is to do radiographic assessment of every sonographic positive hip.

Physiological load and posture control thresholds.

The aim of the study was to evaluate the influence of the physiological load on postural control. Special attention was directed toward the identifying the intensity level in which the major deterioration in balance abilities occurs. Thirty subjects randomly divided into two groups performed multistage all-out exertion protocol on cycle-ergometer with measurements of ventilatory-metabolic and subjective parameters of exertion. Each stage lasted three minutes and was followed with three minute breaks during which the subjects underwent the static (keeping the cursor in the center of the screen) and the dynamic balance testing (following the cursor clockwise or counter clock wise by body movements) on balance platform. In a control group, the protocol encompassed only balance testing procedures followed by 3 min rest. After the completion of the testing procedures, the five intensity zones were determined according to the ventilatory-metabolic parameters. The significant differences in both static and dynamic balance tests were found between the test stages in exercising group. The post hoc analyses revealed the significant negative effect of exercise on the static balance with three visible "balance thresholds". The first threshold was at the rest to work transition, the second at the anaerobic threshold and the third at the maximal exertion level. The dynamic balance was also negatively affected with exercise, however no "balance thresholds" were clearly identified. No significant changes in neither static nor dynamic balance abilities were observed in the control group so the changes in the experimental group could have been attributed to the exercise intensity.

The "cello technique": a new technique for ultrasound-assisted calcaneoplasty.

The "cello technique" is a new calcaneoplasty technique for the treatment of Haglund disease. It is an ultrasound-assisted technique for resection of the posterosuperior part of the calcaneus. It is possible to resect the posterosuperior part of the calcaneus under direct ultrasound control with the patient in the prone position, with a dorsally positioned ultrasound probe, in line with the Achilles tendon fibers (sagittal line), and with the abrader in the posteromedial working portal. We describe in detail the technique for this new procedure in foot and ankle surgery. This innovative technique offers the possibility of expanding the indications for ultrasound-guided surgery in other fields of orthopaedic surgery.

Flat-footedness is not a disadvantage for athletic performance in children aged 11 to 15 years.

OBJECTIVE: Because the controversy about the relation of foot morphology and foot function is still present, we find it surprising that there are no studies published dealing with motor skills and athletic performance in flat-footed school children. Our aim in this study was to determine if there is an association between the degree of foot flatness and several motor skills that are necessary for sport performance. METHODS: The feet of 218 children aged 11 to 15 years were scanned, and the arch index was determined. The value of the arch index was corrected for the influence of age, and then the entire sample was categorized into 4 groups according to the flatness of their feet. The children were tested for eccentric-concentric contraction and hopping on a Kistler force platform, speed-coordination polygon (Newtest system), balance (3 tests), toe flexion (textile crunching), tiptoe standing angle, and repetitive leg movements. Altogether, 17 measures of athletic performance were measured. RESULTS: No significant correlations between the arch height and 17 motor skills were found. Categorizing the sample into 4 groups did not reveal any differences between the groups in athletic performance. Also, several multivariate analysis of variance sets of multiple independent variables referring to a particular motor ability were not found to be significant. The differences were not found even after comparing only the 2 extreme groups, meaning children with very low and children with very high arches. CONCLUSIONS: No disadvantages in sport performance originating from flat-footedness were confirmed. Children with flat and children with "normal" feet were equally successful at accomplishing all motor tests; thus, we suggest that there is no need for treatment of flexible flat feet with the sole purpose of improving athletic performance, as traditionally advised by many.

Intra-articular calcaneal fracture in a 14-year-old competing skier: case report.

Intra-articular calcaneal fracture as a skiing injury in children is extremely rare. We report on what we believe is a unique and previously unreported mechanism of a skiing injury, which caused intra-articular calcaneal fracture in a young competing skier, a member of the Croatian national ski team. This 14-year-old boy sustained a heel injury while training for giant slalom. There was no fall on the heel or obvious axial force that could have caused this type of calcaneal fracture. The skier had sophisticated equipment and used carving skies. We speculated that, when the skier tried to establish the lost balance during the fall, a violent contraction of triceps muscle occurred. Instead of an injury of a well-protected tuber or Achilles tendon, the strong pulling force of the Achilles tendon was transmitted more distally and anteriorly, generating axial compression force, which caused an intra-articular fracture of the calcaneus bone. Obviously, the existing ski boot did not sufficiently protect the calcaneus bone. We postulate that the calcaneal tuber and Achilles tendon were protected on the expense of the intra-articular calcaneal fracture. Our case warns of the possibility of a serious foot injury in young top skiers in spite of extensive improvement in the ski equipment. Sophisticated carving skis could be a contributing factor to an injury.