Proprioceptive performance of bilateral upper and lower limb joints: side-general and site-specific effects

Superiority of the left upper limb in proprioception tasks performed by right-handed individuals has been attributed to better utilization of proprioceptive information by a non-preferred arm/hemisphere system. However, it is undetermined whether this holds for multiple upper and lower limb joints. Accordingly, the present study tested active movement proprioception at four pairs of upper and lower limb joints, after selecting twelve participants with both strong right arm and right leg preference. A battery of versions of the active movement extent discrimination apparatus were employed to generate the stimuli for movements of different extents at the ankle, knee, shoulder and fingers on the right and left sides of the body, and discrimination scores were derived from participants' responses. Proprioceptive performance on the non-preferred left side was significantly better than the preferred right side at all four joints tested (overall F 1, 11 = 36.36, p < 0.001, partial η (2) = 0.77). In the 8 × 8 matrix formed by all joints, only correlations between the proprioceptive accuracy scores for the right and left sides at the same joint were significant (ankles 0.93, knees 0.89, shoulders 0.87, fingers 0.91, p ≤ 0.001; all others r ≤ 0.40, p ≥ 0.20). The results point to both a side-general effect and a site-specific effect in the integration of proprioceptive information during active movement tasks, whereby the non-preferred limb/hemisphere system is specialized in the utilization of the best proprioceptive sources available at each specific joint, but the combination of sources employed differs between body sites.

Prediction of chronicity of anterior cruciate ligament tear using MRI findings

Background

The estimation of anterior cruciate ligament (ACL) tear is required in certain cases involving legal and financial administration, such as the worker's compensation and/or insurance. The aim of this study is to propose and evaluate a quantitative evaluation instrument to estimate the chronicity of the ACL tear, based on the four magnetic resonance imaging (MRI) findings.

Methods

One hundred and fifty one cases of complete ACL tear confirmed by arthroscopy were divided into 4 groups according to the time from ACL injury to MRI acquisition: acute (< 6 weeks), subacute (6 weeks to 3 months), intermediate (3 months to 1 year), and chronic (> 1 year). The four MRI findings including ACL morphology, joint effusion, posterior cruciate ligament angle, and bone bruise were analyzed for temporal changes among the 4 groups. Binary logistic regression equations were formulated using the MRI findings to estimate the chronicity of ACL tear in a quantitative manner, and the accuracy of the formulated regression equations was evaluated.

Results

The four MRI findings showed substantial temporal correlation with the time-limits of ACL injury to be included in the estimation model. Three predictive binary logistic equations estimated the probability of the ACL injury for the three cutoff time-limits of 6 weeks, 3 months, and 1 year with accuracies of 82.1%, 89.4%, and 89.4%, respectively.

Conclusions

A series of predictive logistic equations were formulated to estimate the chronicity of ACL tear using 4 MRI findings with chronological significance.

Exergaming and static postural control in individuals with a history of lower limb injury

CONTEXT

Therapeutic exercise programs that incorporate real-time feedback have been reported to enhance outcomes in patients with lower extremity joint injuries. The Wii Fit has been purported to improve balance, strength, flexibility, and fitness.

OBJECTIVE

To determine the effects of Wii Fit rehabilitation on postural control and self-reported function in patients with a history of lower limb injury.

DESIGN

Single-blinded, randomized controlled trial.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-eight physically active participants with a history of lower limb injuries were randomly assigned to 1 of 3 groups (9 Wii Fit, 10 traditional, 9 control).

INTERVENTION(S)

Intervention groups performed supervised rehabilitation 3 d/wk for a total of 12 sessions.

MAIN OUTCOME MEASURE(S)

Time to boundary (TTB) and the Star Excursion Balance Test (SEBT) were conducted at baseline, 2 weeks, and 4 weeks. Self-reported function was measured at baseline and 4-week follow-up. Between-groups differences were compared using repeated-measures multivariate analysis of variance.

RESULTS

With the eyes open, both intervention groups improved (P < .05) in the mean and the SD of the TTB anterior-posterior minima. In the eyes-closed condition, a time main effect (P < .05) for absolute TTB medial-lateral minima was observed. A time main effect was also noted in the posteromedial and posterolateral reach directions of the SEBT. When the scores for each group were pooled, improvement (P < .05) in self-reported function was demonstrated at 4-week follow-up.

CONCLUSIONS

Rehabilitation using the Wii Fit and traditional exercises improved static postural control in patients with a history of lower extremity injury.

Test-retest and interrater reliability of the functional movement screen

CONTEXT

The Functional Movement Screen (FMS) is a popular test to evaluate the degree of painful, dysfunctional, and asymmetric movement patterns. Despite great interest in the FMS, test-retest reliability data have not been published.

OBJECTIVE

To assess the test-retest and interrater reliability of the FMS and to compare the scoring by 1 rater during a live session and the same session on video.

DESIGN

Cross-sectional study.

SETTING

Human performance laboratory in the sports medicine center.

PATIENTS OR OTHER PARTICIPANTS

A total of 21 female (age = 19.6 ± 1.5 years, height = 1.7 ± 0.1 m, mass = 64.4 ± 5.1 kg) and 18 male (age = 19.7 ± 1.0 years, height = 1.9 ± 0.1 m, mass = 80.1 ± 9.9 kg) National Collegiate Athletic Association Division IA varsity athletes volunteered.

INTERVENTION(S)

Each athlete was tested and retested 1 week later by the same rater who also scored the athlete's first session from a video recording. Five other raters scored the video from the first session.

MAIN OUTCOME MEASURE(S)

The Krippendorff α (K α) was used to assess the interrater reliability, whereas intraclass correlation coefficients (ICCs) were used to assess the test-retest reliability and reliability of live-versus-video scoring.

RESULTS

Good reliability was found for the test-retest (ICC = 0.6), and excellent reliability was found for the live-versus-video sessions (ICC = 0.92). Poor reliability was found for the interrater reliability (K α = .38).

CONCLUSIONS

The good test-retest and high live-versus-video session reliability show that the FMS is a usable tool within 1 rater. However, the low interrater K α values suggest that the FMS within the limits of generalization should not be used indiscriminately to detect deficiencies that place the athlete at greater risk for injury. The FMS interrater reliability may be improved with better training for the rater.

Topical menthol, ice, peripheral blood flow, and perceived discomfort

CONTEXT

Injury management commonly includes decreasing arterial blood flow to the affected site in an attempt to reduce microvascular blood flow and edema and limit the induction of inflammation. Applied separately, ice and menthol gel decrease arterial blood flow, but the combined effects of ice and menthol gel on arterial blood flow are unknown.

OBJECTIVES

To compare radial artery blood flow, arterial diameter, and perceived discomfort before and after the application of 1 of 4 treatment conditions.

DESIGN

Experimental crossover design.

SETTING

Clinical laboratory. PARTICIPANTS OR OTHER PARTICIPANTS: Ten healthy men, 9 healthy women (mean age = 25.68 years, mean height = 1.73 m, mean weight = 76.73 kg).

INTERVENTION(S)

Four treatment conditions were randomly applied for 20 minutes to the right forearm of participants on 4 different days separated by at least 24 hours: (1) 3.5 mL menthol gel, (2) 0.5 kg of crushed ice, (3) 3.5 mL of menthol gel and 0.5 kg of crushed ice, or (4) no treatment (control).

MAIN OUTCOME MEASURE(S)

Using high-resolution ultrasound, we measured right radial artery diameter (cm) and blood flow (mL/min) every 5 minutes for 20 minutes after the treatment was applied. Discomfort with the treatment was documented using a 1-to-10 intensity scale.

RESULTS

Radial artery blood flow decreased (P < .05) from baseline in the ice (-20% to -24%), menthol (-17% to -24%), and ice and menthol (-36% to -39%) treatments but not in the control (3% to 9%) at 5, 10, and 15 minutes. At 20 minutes after baseline, only the ice (-27%) and combined ice and menthol (-38%) treatments exhibited reductions in blood flow (P < .05). Discomfort was less with menthol than with the ice treatment at 5, 10, and 20 minutes after application (P < .05). Arterial diameter and heart rate did not change.

CONCLUSIONS

The application of 3.5 mL of menthol was similar to the application of 0.5 kg of crushed ice in reducing peripheral blood flood. Combining crushed ice with menthol appeared to have an additive effect on reducing blood flow.

Various methods for assessing static lower extremity alignment: implications for prospective risk-factor screenings

CONTEXT

Accurate, efficient, and reliable measurement methods are essential to prospectively identify risk factors for knee injuries in large cohorts.

OBJECTIVE

To determine tester reliability using digital photographs for the measurement of static lower extremity alignment (LEA) and whether values quantified with an electromagnetic motion-tracking system are in agreement with those quantified with clinical methods and digital photographs.

DESIGN

Descriptive laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-three individuals participated and included 17 (10 women, 7 men; age = 21.7 ± 2.7 years, height = 163.4 ± 6.4 cm, mass = 59.7 ± 7.8 kg, body mass index = 23.7 ± 2.6 kg/m2) in study 1, in which we examined the reliability between clinical measures and digital photographs in 1 trained and 1 novice investigator, and 16 (11 women, 5 men; age = 22.3 ± 1.6 years, height = 170.3 ± 6.9 cm, mass = 72.9 ± 16.4 kg, body mass index = 25.2 ± 5.4 kg/m2) in study 2, in which we examined the agreement among clinical measures, digital photographs, and an electromagnetic tracking system.

INTERVENTION(S)

We evaluated measures of pelvic angle, quadriceps angle, tibiofemoral angle, genu recurvatum, femur length, and tibia length. Clinical measures were assessed using clinically accepted methods. Frontal- and sagittal-plane digital images were captured and imported into a computer software program. Anatomic landmarks were digitized using an electromagnetic tracking system to calculate static LEA.

MAIN OUTCOME MEASURE(S)

Intraclass correlation coefficients and standard errors of measurement were calculated to examine tester reliability. We calculated 95% limits of agreement and used Bland-Altman plots to examine agreement among clinical measures, digital photographs, and an electromagnetic tracking system.

RESULTS

Using digital photographs, fair to excellent intratester (intraclass correlation coefficient range = 0.70-0.99) and intertester (intraclass correlation coefficient range = 0.75-0.97) reliability were observed for static knee alignment and limb-length measures. An acceptable level of agreement was observed between clinical measures and digital pictures for limb-length measures. When comparing clinical measures and digital photographs with the electromagnetic tracking system, an acceptable level of agreement was observed in measures of static knee angles and limb-length measures.

CONCLUSIONS

The use of digital photographs and an electromagnetic tracking system appears to be an efficient and reliable method to assess static knee alignment and limb-length measurements.

Outcomes of minimally 1 year follow-up for the arthroscopic Remplissage technique with Hill-Sachs lesion

PURPOSE

We evaluated minimal 1 year follow-up results for the Remplissage technique to fill a Hill-Sachs lesion with anterior instability.

METHODS

The subjects were 12 patients, who could be followed-up for more than 12 months after the "Remplissage" procedures in our hospital from August 2008 to May 2010. Their mean age was 28.6 years old and the mean follow-up was 19 months. The evaluations included the ROM, the ASES score, the KSSI score, the ROWE score and postoperative MRI.

RESULTS

On the postoperative functional evaluation after an average 16 months, the ASES score improved 51.4 in preoperative to 86.6 in postoperatively, the KSSI score improved from 46.6 preoperatively to 84.9 postoperatively and the ROWE score improved from 43.6 preoperatively to 91.4 postoperatively. After an average 14 months for all the cases, the range of movement was nearly in the normal range which is 174.3 ± 5.04 (170-180) degrees in foreward flexion, and 56.4 ± 9.60 (50-60) degrees in external rotation.

CONCLUSION

For recurrent shoulder instability with a large Hill-Sachs lesion, the Remplissage technique has a good outcome after more than 1 year follow-up in terms of shoulder stability, and the clinical and functional results.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Technical considerations for surgical intervention of Jones fractures

Jones fractures are a common injury treated by foot and ankle surgeons. Surgical intervention is recommended because of the high rate of delayed union, nonunion, and repeat fracture, when treated conservatively. Percutaneous intramedullary screw fixation is commonly used in the treatment of these fractures. We present techniques that can increase the surgical efficiency and decrease the complications associated with percutaneous delivery of internal fixation.

Selective activation of the infraspinatus muscle

CONTEXT

To improve selective infraspinatus muscle strength and endurance, researchers have recommended selective shoulder external-rotation exercise during rehabilitation or athletic conditioning programs. Although selective strengthening of the infraspinatus muscle is recommended for therapy and training, limited information is available to help clinicians design a selective strengthening program.

OBJECTIVE

To determine the most effective of 4 shoulder external-rotation exercises for selectively stimulating infraspinatus muscle activity while minimizing the use of the middle trapezius and posterior deltoid muscles.

DESIGN

Cross-sectional study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 30 healthy participants (24 men, 6 women; age = 22.6 ± 1.7 years, height = 176.2 ± 4.5 cm, mass = 65.6 ± 7.4 kg) from a university population.

INTERVENTION(S)

The participants were instructed to perform 4 exercises: (1) prone horizontal abduction with external rotation (PER), (2) side-lying wiper exercise (SWE), (3) side-lying external rotation (SER), and (4) standing external-rotation exercise (STER).

MAIN OUTCOME MEASURE(S)

Surface electromyography signals were recorded from the infraspinatus, middle trapezius, and posterior deltoid muscles. Differences among the exercise positions were tested using a 1-way repeated-measures analysis of variance with Bonferroni adjustment.

RESULTS

The infraspinatus muscle activity was greater in the SWE (55.98% ± 18.79%) than in the PER (46.14% ± 15.65%), SER (43.38% ± 22.26%), and STER (26.11% ± 15.00%) (F3,87 = 19.97, P < .001). Furthermore, the SWE elicited the least amount of activity in the middle trapezius muscle (F3,87 = 20.15, P < .001). Posterior deltoid muscle activity was similar in the SWE and SER but less than that measured in the PER and STER (F3,87 = 25.10, P < .001).

CONCLUSIONS

The SWE was superior to the PER, SER, and STER in maximizing infraspinatus activity with the least amount of middle trapezius and posterior deltoid activity. These findings may help clinicians design effective exercise programs.

Dehydration and performance on clinical concussion measures in collegiate wrestlers

CONTEXT

The effects of dehydration induced by wrestling-related weight-cutting tactics on clinical concussion outcomes, such as neurocognitive function, balance performance, and symptoms, have not been adequately studied.

OBJECTIVE

To evaluate the effects of dehydration on the outcome of clinical concussion measures in National Collegiate Athletic Association Division I collegiate wrestlers.

DESIGN

Repeated-measures design.

SETTING

Clinical research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-two Division I healthy collegiate male wrestlers (age = 20.0 ± 1.4 years; height = 175.0 ± 7.5 cm; baseline mass = 79.2 ± 12.6 kg).

INTERVENTION(S)

Participants completed preseason concussion baseline testing in early September. Weight and urine samples were also collected at this time. All participants reported to prewrestling practice and postwrestling practice for the same test battery and protocol in mid-October. They had begun practicing weight-cutting tactics a day before prepractice and postpractice testing. Differences between these measures permitted us to evaluate how dehydration and weight-cutting tactics affected concussion measures.

MAIN OUTCOME MEASURES

Sport Concussion Assessment Tool 2 (SCAT2), Balance Error Scoring System, Graded Symptom Checklist, and Simple Reaction Time scores. The Simple Reaction Time was measured using the Automated Neuropsychological Assessment Metrics.

RESULTS

The SCAT2 measurements were lower at prepractice (P = .002) and postpractice (P < .001) when compared with baseline. The BESS error scores were higher at postpractice when compared with baseline (P = .015). The GSC severity scores were higher at prepractice (P = .011) and postpractice (P < .001) than at baseline and at postpractice when than at prepractice (P = .003). The number of Graded Symptom Checklist symptoms reported was also higher at prepractice (P = .036) and postpractice (P < .001) when compared with baseline, and at postpractice when compared with prepractice (P = .003).

CONCLUSIONS

Our results suggest that it is important for wrestlers to be evaluated in a euhydrated state to ensure that dehydration is not influencing the outcome of the clinical measures.

Enhanced hyaline cartilage matrix synthesis in collagen sponge scaffolds by using siRNA to stabilize chondrocytes phenotype cultured with bone morphogenetic protein-2 under hypoxia

Cartilage healing by tissue engineering is an alternative strategy to reconstitute functional tissue after trauma or age-related degeneration. However, chondrocytes, the major player in cartilage homeostasis, do not self-regenerate efficiently and lose their phenotype during osteoarthritis. This process is called dedifferentiation and also occurs during the first expansion step of autologous chondrocyte implantation (ACI). To ensure successful ACI therapy, chondrocytes must be differentiated and capable of synthesizing hyaline cartilage matrix molecules. We therefore developed a safe procedure for redifferentiating human chondrocytes by combining appropriate physicochemical factors: hypoxic conditions, collagen scaffolds, chondrogenic factors (bone morphogenetic protein-2 [BMP-2], and insulin-like growth factor I [IGF-I]) and RNA interference targeting the COL1A1 gene. Redifferentiation of dedifferentiated chondrocytes was evaluated using gene/protein analyses to identify the chondrocyte phenotypic profile. In our conditions, under BMP-2 treatment, redifferentiated and metabolically active chondrocytes synthesized a hyaline-like cartilage matrix characterized by type IIB collagen and aggrecan molecules without any sign of hypertrophy or osteogenesis. In contrast, IGF-I increased both specific and noncharacteristic markers (collagens I and X) of chondrocytes. The specific increase in COL2A1 gene expression observed in the BMP-2 treatment was shown to involve the specific enhancer region of COL2A1 that binds the trans-activators Sox9/L-Sox5/Sox6 and Sp1, which are associated with a decrease in the trans-inhibitors of COL2A1, c-Krox, and p65 subunit of NF-kappaB. Our procedure in which BMP-2 treatment under hypoxia is associated with a COL1A1 siRNA, significantly increased the differentiation index of chondrocytes, and should offer the opportunity to develop new ACI-based therapies in humans.

Recent advances in computational mechanics of the human knee joint

Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling.

Stage-specific embryonic antigen-4 is not a marker for chondrogenic and osteogenic potential in cultured chondrocytes and mesenchymal progenitor cells

One important challenge for regenerative medicine is to produce a clinically relevant number of cells with consistent tissue-forming potential. Isolation and expansion of cells from skeletal tissues results in a heterogeneous population of cells with variable regenerative potential. A more consistent tissue formation could be achieved by identification and selection of potent progenitors based on cell surface molecules. In this study, we assessed the expression of stage-specific embryonic antigen-4 (SSEA-4), a classic marker of undifferentiated stem cells, and other surface markers in human articular chondrocytes (hACs), osteoblasts, and bone marrow-derived mesenchymal stromal cells (bmMSCs) and characterized their differentiation potential. Further, we sorted SSEA-4-expressing hACs and followed their potential to proliferate and to form cartilage in vitro. Cells isolated from cartilage and bone exhibited remarkably heterogeneous SSEA-4 expression profiles in expansion cultures. SSEA-4 expression levels increased up to ∼5 population doublings, but decreased following further expansion and differentiation cultures; levels were not related to the proliferation state of the cells. Although SSEA-4-sorted chondrocytes showed a slightly better chondrogenic potential than their SSEA-4-negative counterparts, differences were insufficient to establish a link between SSEA-4 expression and chondrogenic potential. SSEA-4 levels in bmMSCs also did not correlate to the cells' chondrogenic and osteogenic potential in vitro. SSEA-4 is clearly expressed by subpopulations of proliferating somatic cells with a MSC-like phenotype. However, the predictive value of SSEA-4 as a specific marker of superior differentiation capacity in progenitor cell populations from adult human tissue and even its usefulness as a stem cell marker appears questionable.

Randomized controlled trial of the effects of a trunk stabilization program on trunk control and knee loading

BACKGROUND

Many athletic maneuvers involve coordination of movement between the lower and upper extremities, suggesting that better core muscle use may lead to improved athletic performance and reduced injury risk.

PURPOSE

To determine to what extent a training program with quasistatic trunk stabilization (TS) exercises would improve measures of core performance, leg strength, agility, and dynamic knee loading compared with a program incorporating only resistance training (RT).

METHODS

Thirty-seven male subjects were randomly assigned to either an RT-only or a resistance and TS training program, each lasting 6 wk. Core strength and endurance, trunk control, knee loading during unanticipated cutting, leg strength, and agility were collected pre- and posttraining.

RESULTS

Between-group analyses showed that the TS group significantly improved only core endurance when compared with the RT group (side bridge, P = 0.050). Within-group analyses showed that the TS group improved lateral core strength (maximum pull, cable on nondominant side; 44.5 ± 61.3 N, P = 0.037). Both groups increased leg strength (deadlift 1 repetition maximum; TS: 55.1 ± 46.5 lb, P = 0.003; RT: 33.4 ± 17.5 lb, P < 0.001) and decreased sagittal plane trunk control (sudden force release test; cable in front; TS: 2.54° ± 3.68°, P = 0.045; RT: 3.47° ± 2.83°, P = 0.004), but only the RT group decreased lateral trunk control (sudden force release; cable on dominant side; 1.36° ± 1.65°, P = 0.029). The RT group improved standing broad jump (73.2 ± 108.4 mm, P = 0.049) but also showed increased knee abduction moment during unanticipated cutting (1.503-fold increase (percentage body weight × height), P = 0.012).

CONCLUSIONS

Quasistatic TS exercises did not improve core strength, trunk control, or knee loading relative to RT potentially because of a lack of exercises, including unexpected perturbations and dynamic movement. Together, these results suggest the potential importance of targeted trunk control training to address these known anterior cruciate ligament injury risk factors.

What predicts functional outcome after treatment for patellofemoral pain?

PURPOSE

Although physical therapy is known to be effective in treating patellofemoral pain (PFP), there is considerable individual variation in the treatment response. It is unclear why some patients benefit from a specific treatment while others do not experience improvement. This study, using a prospective study design, aims to identify factors that could predict the short-term functional outcome and account for the variation frequently seen in the outcome after conservative treatment of PFP.

METHODS

Thirty-six patients (20 female and 16 male with a mean age of 23.8 ± 6.7 yr) followed a physical therapy rehabilitation program of 7 wk. Before this treatment, all patients were evaluated on subjective symptoms (pain on visual analog scales in millimeters) and functional performance (step test expressed as highest level, single-legged hop test in centimeters, and triple-hop test in centimeters). The concentric and eccentric knee extensor strength at 60°.s(-1) and 240°.s(-1) (N.m) were measured as well as the quadriceps muscle size by calculating the cross-sectional area (cm(2)) with magnetic resonance imaging. The success of the treatment was evaluated by the functional Kujala anterior knee pain scale. A linear regression model was used to identify predisposing factors for the functional outcome.

RESULTS

The total quadriceps cross-sectional area (P = 0.010), the eccentric average peak torque at 60°.s(-1) (P = 0.015), and the frequency of pain at baseline (P = 0.012) have been indicated as predisposing variables in the short-term functional outcome after a physical therapy rehabilitation program for PFP (adjusted R(2) = 0.46).

CONCLUSION

Patients with a greater quadriceps muscle size, lower eccentric knee strength, and less pain have a better short-term functional outcome after conservative treatment for PFP.

Arthroscopic technique for treatment of femoroacetabular impingement

With an increasing understanding of femoroacetabular impingement (FAI) and advancement of the surgical treatment in patients with FAI, various techniques have been published. Successful outcome after arthroscopic hip surgery depends on appropriately reshaping the bony architecture to allow for improved range of motion before impingement symptoms occur, with special attention to preserve the labrum and restore its function. We present our surgical technique for the arthroscopic treatment of FAI.

Traumatic and non-traumatic isolated horizontal meniscal tears of the knee in patients less than 40 years of age

PURPOSE

The aim of this study is to analyze the characteristics of isolated horizontal meniscal tears in young patients and compared traumatic and non-traumatic isolated horizontal meniscal tear without other type of meniscal tear.

METHODS

Forty patients who underwent partial meniscectomy with isolated horizontal meniscal tears and followed up for more than 2 years were divided into two groups according to the presence of distinct previous traumatic events (defined as contusion or sprain) to the knees. Analyzed variables included in this descriptive statistics were involved side of knee and location of meniscus, physical examinations (joint line tenderness and McMurray's testing), subjective International Knee Documentation Committee (IKDC) criteria, and Lysholm functional questionnaires.

RESULTS

Twenty-two of the forty patients (55 %) had distinct previous traumatic events. Fourteen cases (63.6 %) in traumatic group and 14 cases (77.8 %) in non-traumatic group are involved non-dominant knees during locomotion or playing sports. Twenty patients (90.9 %) in traumatic group and eight patients (44.4 %) in non-traumatic group presented with tear in the midportion of the medial meniscus on arthroscopic findings (p < 0.01). Six patients (60.0 %) in traumatic group and twelve patients (85.7 %) in non-traumatic group had meniscal cysts on arthroscopic findings at the time of surgery (p < 0.01). There was no statistic difference between the two groups with respect to physical examinations, subjective IKDC scores, and Lysholm functional scores.

CONCLUSIONS

Isolated horizontal meniscal tears in young patients predominantly involved non-dominant knees and medial meniscus. Anterior aspect of medial meniscus was more frequently involved in traumatic group. Meniscal cysts were more frequently showed in non-traumatic group.

FS-3D-FISP for the diagnosis of ankle impingement syndrome and the evaluation of clinical outcomes of arthroscopic surgery

This study aimed to assess the diagnostic value of three types of MRI sequences and to observe the clinical outcomes of arthroscopy surgery for ankle joint impingement syndrome. Ankle joint impingement syndrome was confirmed by FSE-T2WI, FSE-PDWI, and FS-3D-FISP MRI in 23 patients with arthroscopically proven ankle impingement. All 23 patients underwent arthroscopic surgery and the ankle joint function was evaluated before, 1 week after and 6 months after the operation. The patients were followed-up for 12-64 months (average 28 months). There was no significant difference in ankle function score between preoperatively and 1 week postoperatively, but 86.96 % patients got overall excellent or good scores 6 months after the surgery, significantly higher than before the surgery. The FS-3D-FISP MRI exhibited a good consistency with arthroscopic examination and had higher sensitivity and specificity for the diagnosis of ankle impingement than FSE-T2WI and FSE-PDWI. In summary, arthroscopy surgery for ankle impingement syndrome has several advantages such as good efficacy, minimal trauma, quick recovery, and much less complications. The preoperative FS-3D-FISP MRI allows accurate diagnosis and positioning of ankle impingement syndrome.

The effect of moving point of contact stimulation on chondrocyte gene expression and localization in tissue engineered constructs

Tissue engineering is a promising approach for articular cartilage repair. However, using current technologies, the developed engineered constructs generally do not possess an organized superficial layer, which contributes to the tissue's durability and unique mechanical properties. In this study, we investigated the efficacy of applying a moving point of contract-type stimulation (MPS) to stimulate the production of a superficial-like layer in the engineered constructs. MPS was applied to chondrocyte-agarose hydrogels at a frequency of 0.5, 1 or 2 Hz, under a constant compressive load of 10 mN for durations between 5 and 60 min over 3 consecutive days. Expression and localization of superficial zone constituents was conducted by qRT-PCR and in situ hybridization. Finite element modeling was also constructed to gain insight into the relationship between the applied stimulus and superficial zone constituent expression. Gene expression of superficial zone markers were affected in a frequency dependent manner with a physiologic frequency of 1 Hz producing maximal expression of PRG4, biglycan, decorin and collagen II. In situ hybridization revealed that localization of these markers predominantly occurred at 500-1000 μm below the construct surface which correlated to sub-surface strains between 10 and 25% as determined by finite element modeling. These results indicate that while mechanical stimuli can be used to enhance the expression of superficial zone constituents in engineered cartilage constructs, the resultant subsurface loading is a critical factor for localizing expression. Future studies will investigate altering the applied stimulus to further localize superficial zone constituent expression at the construct surface.

Nonoperative treatment for femoroacetabular impingement: a systematic review of the literature

OBJECTIVE

Femoroacetabular impingement (FAI) has been identified as a common cause of hip pain in young adults. However, it is not known whether an effective nonoperative treatment exists and whether there is any evidence to support such a treatment. The purpose of this review is to establish whether nonoperative treatments exist for FAI in the published literature and whether there is any evidence to support their use. TYPE: A systematic review. LITERACY SURVEY: PubMed, Medline, EMBASE, CINAHL, AMED, and Cochrane Library databases were searched by using the following terms: femoroacetabular impingement, femoro-acetabular impingement, and hip impingement. The search was limited to English only but with no time constraints.

METHODOLOGY

The review was undertaken at 2 academic institutions within the United Kingdom; any article that described or provided evidence that related to a nonoperative treatment for FAI was included. Fifty-three articles met our criteria, of which, 48 were review and/or discussion based.

SYNTHESIS

Five articles summarized primary experiments that described or evaluated nonoperative treatment, of which, 3 reported favorable outcomes. Many review and/or discussion articles (31 [65%]) indicated that a trial of conservative care was appropriate. Activity modification was most frequently recommended (39 [81%]), and nearly half promoted physical therapy as a treatment (23 [48%]).

CONCLUSION

The review literature appears to promote initial nonoperative treatment for FAI. Although the available literature with experimental data is limited, there is a suggestion that physical therapy and activity modification confer some benefit to patients. Nonoperative treatment regimens, particularly physical therapy, need to be evaluated more extensively and rigorously, preferably against operative care, to determine the true clinical effectiveness.

International cricket injury surveillance: a report of five teams competing in the ICC Cricket World Cup 2011

BACKGROUND

Injury surveillance is the cornerstone of effective injury management. However, to date no studies using recommended methods and involving multiple nations have been conducted within International Cricket.

AIM

To conduct injury surveillance across multiple teams during the ICC Cricket World Cup 2011.

METHODS

An electronic system, based on the guidelines for injury surveillance in international cricket, was used to record all new injury episodes was used for data collection.

RESULTS

Twenty-three time-loss and 97 non-time-loss injuries were recorded. The injury incidence was 3.7/100 player-days (0.7 time-loss and 3.0 non-time-loss) with time-loss incidence being; for match injury 20.1/1000 player-days, bowling injury 3.3/100 bowling days and batting injuries 2.2/10,000 balls faced. Thigh muscle strain and medical illness were the diagnoses with the highest incidence. Fast bowlers, slow bowlers and batters all had a similar injury prevalence of approximately 5%. The bowling delivery stride was the activity that resulted in the greatest lost time.

CONCLUSIONS

This is the first study to use recommended injury surveillance guidelines to reporting injury rates across multiple teams at a major cricket tournament. Non-time-loss injury incidence appears relatively high and further study of the effect on performance and progression to subsequent time-loss is required. Fast bowler injury prevalence rates are lower than reported elsewhere, however this may be due to the nature of the tournament and match format, which is likely to impose a lower relative workload. In future, data from all competing teams over all formats of the game (Twenty20, ODI and Tests) needs to be analysed to effectively inform injury prevention research and practice.

Acromioclavicular joint separations

Acromioclavicular (AC) joint separations are common injuries of the shoulder girdle, especially in the young and active population. Typically the mechanism of this injury is a direct force against the lateral aspect of the adducted shoulder, the magnitude of which affects injury severity. While low-grade injuries are frequently managed successfully using non-surgical measures, high-grade injuries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as duration of injury and activity level should also be taken into account in an effort to individualize each patient's treatment. A number of surgical techniques have been introduced to manage symptomatic, high-grade injuries. The purpose of this article is to review the important anatomy, biomechanical background, and clinical management of this entity.

Sports injuries of the wrist

Sports injuries involving the hand and wrist are common and, as a result, many different practitioners (athletic trainers, physical therapists, primary care physicians, general orthopedic surgeons) will encounter these injuries. In addition to thorough evaluation, an understanding of typical pathologies seen in the athlete enhances diagnosis and facilitates appropriate, expedient management. These injuries are complex because they can be either acute traumatic or repetitive in origin and often involve both the bony skeleton and soft tissues. This article provides a review of athletic injuries to the wrist with particular focus on physical evaluation and management of the most common and challenging fractures and soft tissue injuries.

Three-dimensional quantification of femoral head shape in controls and patients with cam-type femoroacetabular impingement

An objective measurement technique to quantify 3D femoral head shape was developed and applied to normal subjects and patients with cam-type femoroacetabular impingement (FAI). 3D reconstructions were made from high-resolution CT images of 15 cam and 15 control femurs. Femoral heads were fit to ideal geometries consisting of rotational conchoids and spheres. Geometric similarity between native femoral heads and ideal shapes was quantified. The maximum distance native femoral heads protruded above ideal shapes and the protrusion area were measured. Conchoids provided a significantly better fit to native femoral head geometry than spheres for both groups. Cam-type FAI femurs had significantly greater maximum deviations (4.99 ± 0.39 mm and 4.08 ± 0.37 mm) than controls (2.41 ± 0.31 mm and 1.75 ± 0.30 mm) when fit to spheres or conchoids, respectively. The area of native femoral heads protruding above ideal shapes was significantly larger in controls when a lower threshold of 0.1 mm (for spheres) and 0.01 mm (for conchoids) was used to define a protrusion. The 3D measurement technique described herein could supplement measurements of radiographs in the diagnosis of cam-type FAI. Deviations up to 2.5 mm from ideal shapes can be expected in normal femurs while deviations of 4-5 mm are characteristic of cam-type FAI.

Cervical spinal cord contusion in professional athletes: a case series with implications for return to play

STUDY DESIGN

Retrospective case series.

OBJECTIVE

This report provides long-term follow-up on athletes who have sustained a cervical spinal cord contusion. Their magnetic resonance (MR) image is correlated with clinical signs and symptoms. Mechanism of injury and a hypothesis of etiology are reported.

SUMMARY OF BACKGROUND DATA

Current return-to-play criteria for athletes who sustain a cervical cord contusion are based on expert opinion only. Decision making for this clinical situation in athletes carries significant clinical, legal, and economic ramifications. The natural history, clinical correlation, and effect of surgery for athletic cervical cord contusions have not been established. The mechanism of injury for this entity has historically emphasized axial loading.

METHODS

The case histories, physical examination, and MR images were reviewed for 4 professional athletes. All athletes had documented cervical cord contusions. None of the athletes had an acute disc herniation, fracture, instability, or focal cord compression. All athletes were contacted by telephone to assess symptoms at a minimum follow-up of 2 years after injury.

RESULTS

All 4 athletes had congenital stenosis, defined as lack of CSF signal around the cord on an MR image. All underwent anterior fusions at the level of their contusion. In follow-up, 2 athletes developed new contusions: one more than 5 years later, adjacent to a fusion; and 1, 2 years later, not adjacent to his previous fusion. No athlete developed permanent neurological sequelae. The presence of a contusion did not correlate with athletes' signs and symptoms. The mechanism of injury was hyperextension.

CONCLUSION

It is hypothesized that the horizontal facet orientation of the C3-C4 level, congenital stenosis, and relative hypermobility in extension are the contributing factors in the cause of this clinical entity. An anterior fusion at the C3-C4 level seems to be the most reliable method of preventing or delaying the return of symptoms. Return-to-play guidelines should emphasize the athletes' history of symptoms in context with their MR image because there is poor correlation between the finding of a contusion and the clinical presentation. Recurrence of symptoms is common and the long-term consequences of repeated episodes remain unknown.

Bovine xenograft locking Puddu plate versus tricalcium phosphate spacer non-locking Puddu plate in opening-wedge high tibial osteotomy: a prospective double-cohort study

PURPOSE

The aim of the study was to compare clinical and radiographic outcomes of opening-wedge high tibial osteotomy (HTO) augmented with either xenograft or tricalcium phosphate spacer for the management of medial compartment osteoarthritis (OA) with genu varum.

METHODS

Between 2004 and 2007, we prospectively enrolled 52 patients with medial compartment knee OA who underwent opening-wedge HTO fixed with locking Puddu plate and xenograft (n = 26) or non-locking Puddu plate and tricalcium phosphate spacer (n = 26). The alignment of the lower limb was assessed by measuring the hip-knee-ankle (HKA) angle. Clinical outcomes were assessed with the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, SF-36 and European Quality of Life-5 Dimensions scale. All patients were followed up at six weeks and at three, six, 12 and 24 months post-operatively. Clinical outcomes were assessed preoperatively and at 24 months post-operatively.

RESULTS

All clinical scores improved significantly in both groups after surgery, without any significant difference between the two groups. Immediately after surgery, the HKA angle went from 9.1 ± 5.2° in varus to 3.1 ± 4.8° in valgus (P = 0.01) in the xenograft group, and from 8.5 ± 5.9° in varus to 3.4 ± 4.2° in valgus (P = 0.01) in the tricalcium phosphate group. At the last follow-up, the tricalcium phosphate group showed a significant loss of correction (P = 0.03).

CONCLUSIONS

HTO performed with xenograft locking plate and tricalcium phosphate non-locking plate constructs showed good clinical outcomes. However, the xenograft locking plate construct is superior to the tricalcium phosphate spacer non-locking plate to prevent the loss of correction in the middle term.

Reconstruction of an in vitro niche for the transition from intervertebral disc development to nucleus pulposus regeneration

The nucleus pulposus (NP) plays a prominent role in both the onset and progression of intervertebral disc degeneration. While autologous repair strategies have demonstrated some success, their in vitro culture system is outdated and insufficient for maintaining optimally functioning cells through the required extensive passaging. Consequently, the final population of cells may be unsuitable for the overwhelming task of repairing tissue in vivo and could result in subpar clinical outcomes. Recent work has identified synovium-derived stem cells (SDSCs) as a potentially important new candidate. This population of precursors can promote matrix regeneration and additionally restore the balance of catabolic and anabolic metabolism of surrounding cells. Another promising application is their ability to produce an extracellular matrix in vitro that can be modified via decellularization to produce a tissue-specific substrate for efficient cell expansion, while retaining chondrogenic potential. When combined with hypoxia, soluble factors, and other environmental regulators, the resultant complex microenvironment will more closely resemble the in vivo niche, which further improves the cell capacity, even after extensive passaging. In this review, the adaptive mechanisms NP cells utilize in vivo are considered for insight into what factors are important for constructing a tissue-specific in vitro niche. Evidence for the use of SDSCs for NP regeneration is also discussed. Many aspects of NP behavior are still unknown, which could lead to future work yielding key information on producing sufficient numbers of a high-quality NP-specific population that is able to regenerate deteriorated NP in vivo.

Impaired collagen biosynthesis and cross-linking in aorta of patients with bicuspid aortic valve

Background

Patients with bicuspid aortic valve (BAV) have an increased risk of developing ascending aortic aneurysm. In the present study, collagen homeostasis in nondilated and dilated aorta segments from patients with BAV was studied, with normal and dilated aortas from tricuspid aortic valve (TAV) patients as reference.

Methods and Results

Ascending aortas from 56 patients were used for biochemical and morphological analyses of collagen. mRNA expression was analyzed in 109 patients. Collagen turnover rates were similar in nondilated and dilated aortas of BAV patients, showing that aneurysmal formation in BAV is, in contrast to TAV, not associated with an increased collagen turnover. However, BAV in general was associated with an increased aortic collagen turnover compared with nondilated aortas of TAV patients. Importantly, the ratio of hydroxylysyl pyridinoline (HP) to lysyl pyridinoline (LP), 2 distinct forms of collagen cross‐linking, was lower in dilated aortas from patients with BAV, which suggests that BAV is associated with a defect in the posttranslational collagen modification. This suggests a deficiency at the level of lysyl hydroxylase (PLOD1), which was confirmed by mRNA and protein analyses that showed reduced PLOD1 expression but normal lysyl oxidase expression in dilated aortas from patients with BAV. This suggests that impaired collagen cross‐linking in BAV patients may be attributed to changes in the expression and/or activity of PLOD1.

Conclusions

Our results demonstrate an impaired biosynthesis and posttranslational modification of collagen in aortas of patients with BAV, which may explain the increased aortic aneurysm formation in BAV patients.

Cellular and extracellular matrix changes in anterior cruciate ligaments during human knee aging and osteoarthritis

INTRODUCTION

Anterior cruciate ligament (ACL) degeneration is observed in most osteoarthritis (OA)-affected knee joints. However, the specific spatial and temporal relations of these changes and their association with extracellular matrix (ECM) degeneration are not well understood. The objective of this study was to characterize the patterns and relations of aging-related and OA-associated changes in ACL cells and the ECM.

METHODS

Human knee joints from 80 donors (age 23 through 94) were obtained at autopsy. ACL degeneration was assessed histologically by using a quantitative scoring system. Tissue sections were analyzed for cell density, cell organization, ECM components, ECM-degrading enzymes and markers of differentiation, proliferation, and stem cells.

RESULTS

Total cell number in normal ACL decreased with aging but increased in degenerated ACL, because of the formation of perivascular cell aggregates and islands of chondrocyte-like cells. Matrix metalloproteinase (MMP)-1, -3, and -13 expression was reduced in aging ACL but increased in degenerated ACL, mainly in the chondrocyte-like cells. Collagen I was expressed throughout normal and degenerated ACL. Collagen II and X were detected only in the areas with chondroid metaplasia, which also expressed collagen III. Sox9, Runt-related transcription factor 2 (Runx2), and scleraxis expression was increased in the chondrocyte-like cells in degenerated ACL. Alpha-smooth muscle actin (α-SMA), a marker of myofibroblasts and the progenitor cell marker STRO-1, decreased with aging in normal ACL. In degenerated ACL, the new cell aggregates were positive for α-SMA and STRO-1.

CONCLUSIONS

ACL aging is characterized by reduced cell density and activation. In contrast, ACL degeneration is associated with cell recruitment or proliferation, including progenitor cells or myofibroblasts. Abnormally differentiated chondrocyte-like cell aggregates in degenerated ACL produce abnormal ECM and may predispose to mechanical failure.

The virtuoso foot

The foot and ankle are prone to injury in the performing arts population, not least amongst dancers who require extreme ranges of movement in this area. This is a complex anatomical area which can be vulnerable to wide array of injuries. Many of these injuries stem from the dancer's posture, technique and environmental factors such as footwear and flooring; therefore, a thorough understanding of these by the clinician is important to ensure full rehabilitation and to prevent recurrence. This article presents an overview of the most common injuries seen in the dancer population and explores the underlying postural, technical and environmental factors that need to be addressed for full recovery.

Low-level light-emitting diode therapy increases mRNA expressions of IL-10 and type I and III collagens on Achilles tendinitis in rats

The present study investigated the effects of low-level light-emitting diode (LED) therapy (880 ± 10 nm) on interleukin (IL)-10 and type I and III collagen in an experimental model of Achilles tendinitis. Thirty male Wistar rats were separated into six groups (n = 5), three groups in the experimental period of 7 days, control group, tendinitis-induced group, and LED therapy group, and three groups in the experimental period of 14 days, tendinitis group, LED therapy group, and LED group with the therapy starting at the 7th day after tendinitis induction (LEDT delay). Tendinitis was induced in the right Achilles tendon using an intratendinous injection of 100 μL of collagenase. The LED parameters were: optical power of 22 mW, spot area size of 0.5 cm(2), and irradiation time of 170 s, corresponding to 7.5 J/cm(2) of energy density. The therapy was initiated 12 h after the tendinitis induction, with a 48-h interval between irradiations. The IL-10 and type I and III collagen mRNA expression were evaluated by real-time polymerase chain reaction at the 7th and 14th days after tendinitis induction. The results showed that LED irradiation increased IL-10 (p < 0.001) in treated group on 7-day experimental period and increased type I and III collagen mRNA expression in both treated groups of 7- and 14-day experimental periods (p < 0.05), except by type I collagen mRNA expression in LEDT delay group. LED (880 nm) was effective in increasing mRNA expression of IL-10 and type I and III collagen. Therefore, LED therapy may have potentially therapeutic effects on Achilles tendon injuries.

The acute effects of exercise on the microvascular volume of Achilles tendons in healthy young subjects

BACKGROUND

Real-time harmonic contrast-enhanced ultrasound (CEU) is used in several diseases to visualize the microvascularization in various tissues, due to its high sensitivity.

AIM

The aim of the present study was to investigate whether CEU could be used to detect an increase in the microvascular volume (MV) in healthy tendon tissue in response to exercise comprising a 1-h run.

METHODS

After a bolus injection of the ultrasound contrast SonoVue(®), CEU measurements of (MV) in the Achilles tendon were taken prior to exercise, immediately after a 1-h run, and 24 h after exercise in nine healthy young subjects (seven men and two women) mean age 31 ± 4 years. In addition, the effect of 15 min of arm cycling exercise on the flow within the Achilles tendon was tested in four athletes (mean age 33 ± 6 years) using the CEU method before and after exercise.

RESULTS

The present data show a significant increase in the (MV) of the Achilles tendon for all subjects following the run compared with before exercise. No significant change in (MV) was seen in the Achilles tendon after 15-min arm cycling exercise (P = 0·96). This indicates that the increase in microvascular blood volume within the Achilles tendon in response to running is a local response.

CONCLUSION

The present data reveal that real-time harmonic CEU can be used to determine the MV of healthy Achilles tendons both at rest and after 1 h of running exercise.

Sports injuries among adolescent basketball players according to position on the court

Background

The participation of children and adolescents in sports, including basketball, is becoming increasingly common, and this increased involvement raises concerns about the potential risk of sports injuries.

Objective

To analyze the occurrence of sports injuries among young basketball players according to their position on the court and to associate these injuries with risk factors.

Method

A retrospective, epidemiological study. A sample consisting of 204 basketball players with a mean age of 14.33 ± 1.19 years participated in the study. The players were interviewed using a reported condition questionnaire containing anthropometric and training data as well as information on injuries during the previous 12 months.

Results

The frequency of injury was highest among the shooting guards (47.8%), followed by the centers (34.8%) and point guards (17.4%). Among the 204 participants, 40 players reported a total of 46 injuries, representing 0.22 injuries per participant and 1.15 injuries per injured participant. For the shooting guards and centers, statistically significant differences between injured and non-injured players were found related to age, weight, height, length of time in training and number of weekly practice hours (p < 0.05). For point guards, a statistically significant difference between injured and non-injured players was found based on weight alone (p < 0.05).

Conclusion

The occurrence of injuries among basketball players was low. Injuries were associated with both intrinsic and extrinsic factors among shooting guards and centers, whereas injuries were only associated with weight among point guards.

The metabolic and mechanical costs of step time asymmetry in walking

Animals use both pendular and elastic mechanisms to minimize energy expenditure during terrestrial locomotion. Elastic gaits can be either bilaterally symmetric (e.g. run and trot) or asymmetric (e.g. skip, canter and gallop), yet only symmetric pendular gaits (e.g. walk) are observed in nature. Does minimizing metabolic and mechanical power constrain pendular gaits to temporal symmetry? We measured rates of metabolic energy expenditure and calculated mechanical power production while healthy humans walked symmetrically and asymmetrically at a range of step and stride times. We found that walking with a 42 per cent step time asymmetry required 80 per cent (2.5 W kg(-1)) more metabolic power than preferred symmetric gait. Positive mechanical power production increased by 64 per cent (approx. 0.24 W kg(-1)), paralleling the increases we observed in metabolic power. We found that when walking asymmetrically, subjects absorbed more power during double support than during symmetric walking and compensated by increasing power production during single support. Overall, we identify inherent metabolic and mechanical costs to gait asymmetry and find that symmetry is optimal in healthy human walking.

Stress injury of the acromion: case report and literature review

We report a case of stress injury of the acromion related to golf practicing in a 40-year-old male. Fractures of the scapula are unusual, with stress injury of the acromion being even rarer. The probable mechanism would be a strong contraction of posterior fibers of the deltoid during golf swing. There are few published reports of similar injuries, and to our knowledge, this is the first to demonstrate its features by magnetic resonance imaging. A review of the literature is also presented.

PDGF-BB-induced MT1-MMP expression regulates proliferation and invasion of mesenchymal stem cells in 3-dimensional collagen via MEK/ERK1/2 and PI3K/AKT signaling

Mesenchymal stem cells (MSCs) mobilize membrane type-1 matrix metalloproteinase (MT1-MMP) to traffic through both 3-dimensional (3D) collagen as well as basement membrane barriers, but factors capable of regulating the expression and activity of the protease remain unidentified. Herein, we report that the MT1-MMP-dependent invasive activities of rat MSCs are controlled by PDGF-BB. Furthermore, PDGF-BB also stimulates MSC proliferation in 3D type I collagen via an MT1-MMP-dependent process that is linked to pericellular collagen degradation. PDGF-BB stimulates MT1-MMP expression at both the mRNA and protein levels in concert with ERK1/2 and PI3K/AKT activation. Inhibition of ERK1/2 or PI3K/AKT activity potently suppresses both MT1-MMP-dependent invasive and proliferative activities. Basement membrane invasion is likewise stimulated by PDGF-BB in an MT1-MMP-dependent manner via ERK1/2 and PI3K/AKT signaling. Taken together, these data serve to identify PDGF-BB as an important MSC agonist that controls invasive and proliferative activities via MT1-MMP-dependent processes that are regulated by the ERK1/2 and PI3K/AKT signaling pathways.

Boomerang proximal tibial osteotomy for the treatment of severe varus gonarthrosis

PURPOSE

The purpose of the study was to review the results of modified infratubercle displacement osteotomy in patients with severe varus gonarthrosis and to determine the factors influencing outcomes.

METHODS

A total of 177 knees in 133 patients with severe varus gonarthrosis were treated with infratubercle boomerang-shaped osteotomy, stabilised with dual plates. The mean age of the patients was 63.8 years (range 43-80 years), and the mean follow-up period was 61.4 months (range 24 -139 months). The factors associated with clinical and survival outcomes were analysed including age, gender, body mass index (BMI), preoperative and post-operative femorotibial angle and femorotibial angle at one year after surgery.

RESULTS

Using the Knee Society clinical rating system 149 knees or 84.2 % were rated as having good to excellent results and 21 knees or 15.8 % as having fair to poor results. Overall, the mean preoperative knee score of 33.6 points had improved significantly to 80.7 points at the final follow-up (p < 0.001). Using Kaplan-Meier survivorship analysis the five-year survival was 97.1 % with conversion to arthroplasty or second osteotomy as the end point and 89.2 % with a knee score of under 70 points as the end point. The anatomical femorotibial angle at one year after osteotomy had the most significant positive effect on the clinical (p < 0.001) and survival outcomes for all end points (p = 0.002 for conversion to arthroplasty or second osteotomy and p < 0.001 for knee score less than 70 points).

CONCLUSIONS

The boomerang osteotomy can create adequate valgus alignment in severe varus gonarthrosis. The one-year post-operative knee alignment of 11° valgus provided the most satisfactory results and that between six and 15° valgus the longest survival time.

Management of joint bleeding in hemophilia

Hemarthrosis, the hallmark of severe hemophilia, is the major cause of serious bleeding events, disability and reduced quality of life in patients with factor VIII or factor IX deficiency. Joint bleeding is one of the greatest challenges confronting individuals treating hemophilia, and its economic impact is enormous. This article reviews the current management of hemophilic joint bleeding and discusses the potential impact of novel therapies.

The effect of biceps procedure on the outcome of rotator cuff reconstruction

Purpose. Biceps long head pathology is often associated with rotator cuff tears. The aim of this study was to determine the effect of possible associated biceps procedure on the treatment outcome in rotator cuff repair. Methods. 148 consecutive shoulders operated for isolated full-thickness supraspinatus tendon tear were included. A biceps tenotomy or tenodesis was performed in cases of irritated/frayed and/or unstable biceps tendon. The patients were grouped into three groups according to the biceps procedure (no procedure, tenotomy, and tenodesis). The age-adjusted Constant score was used as an outcome measure. Results. 145 shoulders (98%) were available for final followup. Preoperatively, there was no statistically significant difference in Constant scores. At three months, there was a statistically significant positive change in Constant scores compared with preoperative status in the tenotomy group in women. At one year there was a statistically significant positive change in Constant scores in all groups in both genders. However, there was no statistically significant difference between the groups at one year in either gender. Conclusion. Biceps procedure does not affect the final clinical treatment outcome after rotator cuff repair. Recovery from operative treatment may be faster in tenotomized female patients in cases of encountered biceps pathology.