Evaluation of hop performance in children with anterior cruciate ligament reconstruction using healthy reference data: A cross-sectional study.

BACKGROUND: Hop performance evaluation in children after anterior cruciate ligament (ACL) reconstruction may benefit from comparison to healthy controls. Thus, the purpose was to investigate the hop performance in children one year after ACL reconstruction with a comparison to healthy controls. METHODS: Hop performance data from children with ACL reconstruction one year post-surgery and healthy children were compared. Four one-legged hop test data were analyzed: 1) single hop (SH), 2) 6 m timed hop (6 m-timed), 3) triple hop (TH), and 4) cross-over hop (COH). Outcomes were the best result (longest/fastest hop) from each leg and limb asymmetry. Differences in hop performance between-limbs (operated versus non-operated) and between-groups were estimated. RESULTS: 98 children with ACL reconstruction and 290 healthy children were included. Few statistically significant group differences were observed. Girls with ACL reconstruction outperformed healthy controls in two tests on the operated leg SH, COH) and in three tests on the non-operated leg (SH, TH, COH). However, the girls performed 4-5% worse on the operated leg when compared to the non-operated leg in all hop tests. No statistically significant between-group differences in the limb asymmetry were found. CONCLUSION: The hop performance in children with ACL reconstruction one year post-surgery was largely comparable to the level of healthy controls. Despite this, we cannot exclude that neuromuscular deficits exist among the children with ACL reconstruction. The inclusion of a healthy control group for evaluating hop performance evoked complex findings regarding the ACL reconstructed girls. Thus, they may represent a selected group.

Validation of the colostomy impact score in patients ostomized for a benign condition.

AIM: The colostomy impact (CI) score is a patient-reported outcome measure assessing reduction in health-related quality of life (HRQL) due to a stoma. The score was originally developed and validated in a cohort of rectal cancer survivors with a permanent colostomy. For the CI score to be applied to patients with a colostomy after surgery for a benign condition it must be validated in this patient group. The aim of this study was to assess construct validity and known groups validity of the CI score in patients with a colostomy after surgery for a benign condition. METHOD: In a cross-sectional survey among ostomates in the Capital Region of Denmark, patients completed the CI score and the SF-36 v2 questionnaires. Construct validity was assessed by Pearson's correlation coefficients and known groups validity was assessed by t-test when dividing patients into groups of minor or major CI. RESULTS: The CI score showed a moderate negative correlation with the Physical Component Summary (PCS) of -0.41 and a weak negative correlation with the Mental Component Summary (MCS) of -0.39. The strength of the correlation depended on the underlying condition leading to stoma formation. Differences were significant between the minor and major CI groups in mean PSC and MCS with t-values of 5.32 and 3.86, respectively. CONCLUSION: The CI score is a valid instrument for assessing stoma-related impact on HRQL regardless of the underlying condition leading to stoma formation, and the CI score discriminates meaningfully between groups with known differences in stoma-related reduced HRQL.

Surgical repair of parastomal bulging: a retrospective register-based study on prospectively collected data.

AIM: The aim of this work was to examine (1) the incidence of primary repair, (2) the incidence of recurrent repair and (3) the types of repair performed in patients with parastomal bulging. METHOD: Prospectively collected data on parastomal bulging from the Danish Stoma Database were linked to surgical data on repair of parastomal bulging from the Danish National Patient Register. Survival statistics provided cumulative incidences and time until primary and recurrent repair. RESULTS: In the study sample of 1016 patients with a permanent stoma and a parastomal bulge, 180 (18%) underwent surgical repair. The cumulative incidence of a primary repair was 9% [95% CI (8%; 11%)] within 1 year and 19% [95% CI (17%; 22%)] within 5 years after the occurrence of a parastomal bulge. We found a similar probability of undergoing primary repair in patients with ileostomy and colostomy. For recurrent repair, the 5-year cumulative incidence was 5% [95% CI (3%; 7%)]. In patients undergoing repair, the probability was 33% [95% CI (21%; 46%)] of having a recurrence requiring repair within 5 years. The main primary repair was open or laparoscopic repair with mesh (43%) followed by stoma revision (39%). Stoma revision and repair with mesh could precede or follow one another as primary and recurrent repair. Stoma reversal was performed in 17% of patients. CONCLUSION: Five years after the occurrence of a parastomal bulge the estimated probability of undergoing a repair was 19%. Having undergone a primary repair, the probability of recurrent repair was high. Stoma reversal was more common than expected.

Remodeling of muscle fibers approaching the human myotendinous junction.

The myotendinous junction (MTJ) is at high risk of strain injuries, due to high amounts of energy that is transferred through this structure. The risk of strain injury is significantly reduced by heavy resistance training (HRT), indicating a remodeling capacity of MTJ. We investigated the degree of remodeling of muscle fibers near the human MTJ. In 8 individuals, samples were taken from the semitendinosus and gracilis MTJ and they were stained immunohistochemically for myonuclei (DAPI), fibroblasts (TCF7L2), and satellite cells (CD56). A high portion of the muscle fibers adjacent to the MTJ contained a centrally located myonucleus (47 ± 8%, mean ± SD) and half of the muscle fibers were CD56 positive. The number of satellite cells and fibroblasts were not higher than what has previously been reported from muscle bellies. The immunohistochemical findings suggest that the rate of remodeling of muscle fibers near the MTJ is very high. The finding that there was no increased number of satellite cells and fibroblasts could be explained as a dynamic phenomenon. The effect of HRT should be evaluated in a randomized setting.

Symptom load and individual symptoms before and after repair of parastomal hernia: a prospective single centre study.

AIM: The symptom load and individual symptoms before and after repair of parastomal hernia were investigated. METHOD: Stoma-related symptoms were prospectively recorded before repair of a parastomal hernia and at 10 days and 6 months postoperatively: leakage, skin problems, difficulty with the appliance, limitation of activity, difficulty with clothing, cosmetic complaints, social restriction, erratic action of the stoma, a bearing-down sensation at the site of the stoma and pain. Episodes of intermittent bowel obstruction and difficulty with irrigation were also recorded. Patients were seen at 1, 2 and 3 years and were examined for recurrent parastomal herniation. RESULTS: Of 131 consecutive patients referred to a specialized centre for treatment of parastomal bulging, 61 underwent parastomal hernia repair. Forty-eight patients were treated with the Sugarbaker technique. Six different symptoms were present in more than half the patients before surgery. The overall symptom load decreased significantly from a median of 4 [interquartile range (IQR) 2.5-6] preoperatively to 2 (IQR 1-3) on postoperative day 10 and 1 (IQR 0-2) at 6 months, P < 0.001. The number of symptoms decreased in 93% of patients; in 5% there was no change and in 2% symptoms increased. Skin problems and leakage were the only symptoms that were not significantly reduced. The overall recurrence rate of herniation was 5/48 (10%) at a median of 12 (IQR 6-24) months. CONCLUSION: The preoperative symptom load was high and this fell after repair in over 90% of patients. Recurrence occurred in 10% of patients within 2 years of repair. The study emphasizes the importance of detailed knowledge of the symptoms of parastomal hernia when addressing and managing patients' problems and complaints.

Potential serious bias in National Clinical Databases with low degree of reported follow-up.

We identified reasons for the low follow-up rate in the Danish Knee ligament Reconstruction Register (DKRR) and evaluated its influence on the data quality. All 946 primary ACL-reconstructed patients in the Capital Region of Denmark during 2012 were identified in the databases of 8 participating hospitals. We studied the patient files and compared them to figures reported to the DKRR. 92.5% of the operated patients was registered in DKRR. The 1-year follow-up rate reported to DKRR was 33.4%, and 14.5% filled in patient reported outcomes (KOOS and Tegner) at 1 year. Only 65% had actually been invited for follow-up, but among the patients who had been invited 91% were seen. 41% of existing follow-up data was not reported. Contemporary technology and structured motivation should be introduced to increase validity of data in national clinical databases. Follow-up >90% in the DKRR is realistic if patents are invited and reported. The unreported data is potentially a serious bias. It is suggested that data from clinics with low follow-up should not be used in studies involving outcomes based on national databases because of risk of bias.

Composition and adaptation of human myotendinous junction and neighboring muscle fibers to heavy resistance training.

The myotendinous junction (MTJ) is a common site of strain injury and yet understanding of its composition and ability to adapt to loading is poor. The main aims of this study were to determine the profile of selected collagens and macrophage density in human MTJ and adjoining muscle fibers, and to investigate whether heavy exercise loading would alter this profile. Fifteen individuals scheduled for anterior cruciate ligament repair surgery were randomized into three groups: control, acute or 4 weeks heavy resistance training. MTJ samples were collected from the semitendinosus and gracilis muscles and were sectioned and stained immunohistochemically for collagen types I, III, VI, XII, XIV, XXII, Tenascin-C and CD68. Macrophage density and distribution was evaluated and the amount of each collagen type in muscle and MTJ was graded. Collagen XXII was observed solely at the MTJ, while all other collagens were abundant at the MTJ and in muscle perimysium or endomysium. The endomysial content of collagen XIV, macrophages and Tenascin-C increased following 4 weeks of training. These findings illustrate the heterogeneity of collagen type composition of human MTJ. The increase in collagen XIV following 4 weeks of training may reflect a training-induced protection against strain injuries in this region.

The role of the anterolateral ligament in ACL insufficient and reconstructed knees on rotatory stability: A biomechanical study on human cadavers.

Studies suggest that the anterolateral ligament (ALL) is important for knee stability. The purpose was to clarify ALL's effect on rotatory and anterior-posterior stability in the anterior cruciate ligament (ACL)-insufficient and reconstructed knees and the effect of reconstruction of an insufficient ALL. Eighteen cadaveric knees were included. Stability was tested for intact (+ALL), detached (-ALL) and reconstructed (+ reALL) ALL, with ACL removed (-ACL) and reconstructed (+ACL) in six combinations. All were tested in 0, 30, 60, and 90 °C flexion. Anterior-posterior stability was measured with a rolimeter. Rotation with a torque of 8.85 Nm was measured photographically. The ALL was well defined in 78% of knees. ACL reconstruction had a significant effect on anterior-posterior stability. Detaching the ALL had a significant effect on internal rotatory stability and on anterior-posterior stability in ACL-insufficient knees. Reconstruction of ACL and ALL reestablished knee stability. The appearance of the ALL was not uniform. The ALL was an internal rotational stabilizer. Anatomical ALL reconstruction in combination with ACL reconstruction could reestablish stability. ALL reconstruction might be considered in patients with combined ACL and ALL tears, but the clinical effect should be established in a controlled clinical study.

The human myotendinous junction: an ultrastructural and 3D analysis study.

The myotendinous junction (MTJ) is a specialized structure in the musculotendinous system, where force is transmitted from muscle to tendon. Animal models have shown that the MTJ takes form of tendon finger-like processes merging with muscle tissue. The human MTJ is largely unknown and has never been described in three dimensions (3D). The aim of this study was to describe the ultrastructure of the human MTJ and render 3D reconstructions. Fourteen subjects (age 25 ± 3 years) with isolated injury of the anterior cruciate ligament (ACL), scheduled for reconstruction with a semitendinosus/gracilis graft were included. Semitendinosus and gracilis tendons were stripped as grafts for the ACL reconstruction. The MTJ was isolated from the grafts and prepared for transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy. It was possible to isolate recognizable MTJ tissue from all 14 patients. TEM images displayed similarities to observations in animals: Sarcolemmal evaginations observed as finger-like processes from the tendon and endomysium surrounding the muscle fibers, with myofilaments extending from the final Z-line of the muscle fiber merging with the tendon tissue. The 3D reconstruction revealed that tendon made ridge-like protrusions, which interdigitiated with groove-like indentations in the muscle cell.

A randomised controlled trial of ultrasound-guided blockade of the saphenous nerve and the posterior branch of the obturator nerve for postoperative analgesia after day-case knee arthroscopy.

The purpose of this study was to investigate the effects of blockade of the saphenous nerve and the posterior branch of the obturator nerve in addition to a standard analgesic regimen for patients discharged the same day after knee arthroscopy. The primary outcome was knee pain on flexion during the first 24 postoperative hours, calculated as area under the curve. We allocated 60 patients to ultrasound-guided nerve blocks with either ropivacaine or saline, 30 to each. The median (IQR [range]) pain score on knee flexion in the ropivacaine group 2.0 (1.1-3.7 [0.1-7.1]) was not statistically different to that in the saline group (3.3 (1.7-4.6 [0.3-6.8]), p = 0.06). There were no differences in pain at rest, opioid consumption or function.

Gels and threads: mussel-inspired one-pot route to advanced responsive materials.

An inexpensive one-pot route to self-healing hydrogels with pH-tunable modulus is presented. Hydrogels were formed by reacting tannic acid, trivalent metal ions and polyallylamine. Below pH 8 the hydrogels were supramolecular while above, covalent cross-linking strengthened the hydrogels. From concentrated mixtures, threads were spun, acting as water sensitive mechanical locks.

Dimensionality of the Knee Numeric-Entity Evaluation Score (KNEES-ACL): a condition-specific questionnaire.

The benefit of anterior cruciate ligament (ACL) reconstruction has been questioned based on patient-reported outcome measures (PROMs). Valid interpretation of such results requires confirmation of the psychometric properties of the PROM. Rasch analysis is the gold standard for validation of PROMs, yet PROMs used for ACL reconstruction have not been validated using Rasch analysis. We used Rasch analysis to investigate the psychometric properties of the Knee Numeric-Entity Evaluation Score (KNEES-ACL), a newly developed PROM for patients treated for ACL deficiency. Two-hundred forty-two patients pre- and post-ACL reconstruction completed the pilot PROM. Rasch models were used to assess the psychometric properties (e.g., unidimensionality, local response dependency, and differential item functioning). Forty-one items distributed across seven unidimensional constructs measuring impairment, functional limitations, and psychosocial consequences were confirmed to fit Rasch models. Fourteen items were removed because of statistical lack of fit and inadequate face validity. Local response dependency and differential item functioning were identified and adjusted. The KNEES-ACL is the first Rasch-validated condition-specific PROM constructed for patients with ACL deficiency and patients with ACL reconstruction. Thus, this instrument can be used for within- and between-group comparisons.

Development of the Knee Numeric-Entity Evaluation Score (KNEES-ACL): a condition-specific questionnaire.

Patient-related outcome measures (PROMs) are commonly used to gauge treatment effects in patients with anterior cruciate ligament (ACL) deficiency. Valid measures of specific conditions depend on relevant item content. While item content can be derived either from clinicians (face validity) or from patients, item relevance and comprehensiveness can only be confirmed by the patient (content validity). Focus group and single interviews were conducted with patients' pre- and post-ACL reconstruction in order to construct a condition-specific PROM for the target patients. One hundred fifty-seven items from a previously conducted literature search were used as a basis for content genesis. Content saturation was achieved after three focus groups and seven single interviews. Thirty-eight items from the literature search were directly endorsed, and five modified items were endorsed. Twelve new item themes with verbatim content emerged. Thus, a 55-item pilot PROM consisting of six conceptual domains was assembled. We have constructed a condition-specific PROM for measurement of surgical and non-surgical treatment effects on ACL deficiency. The instrument possesses face and content validity. A pilot survey to assess the psychometric properties will be performed using Rasch measurement theory.

Pain and knee function in relation to degree of bone bruise after acute anterior cruciate ligament rupture.

It is unknown whether the bone bruise that occurs in connection with acute anterior cruciate ligament (ACL) rupture is causing pain and dysfunction. We followed prospectively 17 patients [10 men, seven women, mean age 28 years (range 23-34)] with acute ACL rupture for 2 months. A magnetic resonance imaging (MRI) scan was performed shortly after the injury, and at 2 weeks, 1 month and 2 months. The patients reported the level of pain every day and filled in a Knee injury and Osteoarthritis Outcome Score sheet in connection with MRI. For every MRI of the knee, volume of bone bruise was calculated, and intensity was visually graded. Our study showed a reduction of the pain to 50% approximately 2 weeks after the injury, at which time the bone bruise was at maximum. There was a significant relationship between pain and the volume and intensity of the bone bruise in the medial tibia condyle, as well as pain and the bone bruise volume of the lateral femoral condyle. Patients with bone bruise of the medial tibia and patients with meniscal lesions had more pain. It is suggested that pain and decreased function after acute ACL injury most likely is related to soft tissue and cartilage injury and not to bone bruise.

Ultrasound-guided continuous suprascapular nerve block for adhesive capsulitis: one case and a short topical review.

We present a case with an ultrasound-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the suprascapular nerve (SSN). The patient suffered from a severe and very painful adhesive capsulitis of the left shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low impact passive and guided active mobilization by the performing physiotherapist for three consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlight the possibility of a USG continuous nerve block of the SSN as sufficient pain management in the immediate post-operative period following capsular release of the shoulder. Findings in other painful shoulder conditions and suggestions for future studies are discussed in the text.

Stress fracture in combination with avulsion from the tibia in a marathon runner: a case report.

We report an exceptional case of a tibial stress fracture combined with a large avulsion from the posterior facet of the tibia at the level where the tibialis posterior and soleus muscles insert. This type of injury has not been reported previously. A young healthy male runner experienced a sudden "snap" in the right lower leg 25 km into a marathon and had to leave the race due to increasing pain. The fracture was immediately apparent on plain radiographs. The injury was treated conservatively with 9 weeks in an ROM knee cast and no weight bearing on the affected leg, followed by full recovery. We propose that prolonged muscle tension at the site of tendinous attachment to the bone can cause the development of a stress fracture type of avulsion.

Early osteoarthritis and microdialysis: a novel in vivo approach for measurements of biochemical markers in the perisynovium and intraarticularly.

The microdialysis technique was evaluated as a possible method to obtain local measurements of biochemical markers from knee joints with degenerative changes. Seven patients scheduled for arthroscopy of the knee due to minor to moderate degenerative changes had microdialysis catheters inserted under ultrasonographic guidance, intraarticularly and in the synovium-close tissue. Catheters were perfused at a rate of 2 µl/min for approximately 100 min with a Ringer solution containing radioactively labeled glucose, and the positions of the catheters were later visualized during arthroscopy. All intraarticular catheters and 6/7 subsynovial catheters were positioned correctly. Relative recovery (RR) was intraarticularly 0.64 ± 0.02 (mean ± SEM) and synovium-close 0.54 ± 0.06. Mean values of cartilage oligomeric matrix protein (COMP), aggrecan and glucosyl-galactosyl-pyridinoline in the intraarticular dialysates were 18.1 ± 7.0 U/l, 243.6 ± 108.6 ng/ml and 108.0 ± 29.0 pmol/ml, respectively. COMP and glucosyl-galactosyl-pyridinoline concentrations were significantly higher intraarticularly compared to perisynovial tissue (P < 0.05), whereas for aggrecan, no significant difference was found (P = 0.06). The microdialysis method can be used for intraarticular and subsynovial determination of metabolites in human knees at these sites. The present methodology displays a potential for future studies of simultaneous biochemical changes within and around joints.

From mechanical loading to collagen synthesis, structural changes and function in human tendon.

The adaptive response of connective tissue to loading requires increased synthesis and turnover of matrix proteins, with special emphasis on collagen. Collagen formation and degradation in the tendon increases with both acute and chronic loading, and data suggest that a gender difference exists, in that females respond less than males with regard to an increase in collagen formation after exercise. It is suggested that estrogen may contribute toward a diminished collagen synthesis response in females. Conversely, the stimulation of collagen synthesis by other growth factors can be shown in both animal and human models where insulin-like growth factor 1 (IGF-I) and transforming growth factor-beta-1 (TGF-beta-1) expression increases to accompany or precede an increase in procollagen expression and collagen synthesis. In humans, it can be demonstrated that an increase in the interstitial concentration of TGF-beta, PGE2, IGF-I plus its binding proteins and interleukin-6 takes place after exercise. The increase in IGF-I expression in tendon includes the isoform that has so far been thought only to exist in skeletal muscle (mechano growth factor). The increase in IGF-I and procollagen expression showed a similar response whether the tendon was stimulated by concentric, isometric or eccentric muscle contraction, suggesting that strain rather that stress/torque determines the collagen-synthesis stimulating response seen with exercise. The adaptation time to chronic loading is longer in tendon tissue compared with contractile elements of skeletal muscle or the heart, and only with very prolonged loading are significant changes in gross dimensions of the tendon observed, suggesting that habitual loading is associated with a robust change in the size and mechanical properties of human tendons. An intimate interplay between mechanical signalling and biochemical changes in the matrix is needed in tendon, such that chemical changes can be converted into adaptations in the morphology, structure and material properties.

Rasch analysis of the Knee injury and Osteoarthritis Outcome Score (KOOS): a statistical re-evaluation.

The knee injury and Osteoarthritis Outcome Score (KOOS), based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), is widely used to evaluate subjective outcome in anterior cruciate ligament (ACL) reconstructed patients. However, the validity of KOOS has not been assessed using Rasch analysis. The objective of this study was to evaluate the viability of KOOS as an outcome measure for ACL reconstruction using the partial credit Rasch model. Rasch analysis was applied to 200 KOOS questionnaires completed by patients consecutively tested 20 weeks after ACL reconstruction and subsequent rehabilitation. Rasch analysis showed that of the five proposed subscales in KOOS, only knee-related quality of life (QoL) and sport and recreational related function (Sport/Rec) fulfilled the criteria of a unidimensional measurement scale when applied to these patients. The three subdomains in KOOS extracted from WOMAC did not fulfill these criteria. While the content of KOOS appears to be relevant for knee patients, the psychometric measurement properties of KOOS are insufficient for use on patients 20 weeks subsequent to ACL reconstruction. A new knee measure targeted for these patients could be developed based on the content of KOOS. This study demonstrates that knee measurement instruments constructed for a specific condition cannot necessarily be used on patients with other similar conditions.