The impact of skeletal muscle disuse on distinct echo intensity bands: A retrospective analysis

Echo intensity (EI) is a novel tool for assessing muscle quality. EI has traditionally been reported as the mean of the pixel histogram, with 0 and 255 arbitrary units (A.U.) representing excellent and poor muscle quality, respectively. Recent work conducted in youth and younger and older adults suggested that analyzing specific EI bands, rather than the mean, may provide unique insights into the effectiveness of exercise and rehabilitation interventions. As our previous work showed deterioration of muscle quality after knee joint immobilization, we sought to investigate whether the increase in EI following disuse was limited to specific EI bands. Thirteen females (age = 21 yrs) underwent two weeks of left knee immobilization and ambulated via crutches. B-mode ultrasonography was utilized to obtain images of the immobilized vastus lateralis. The percentage of the total number of pixels within bands of 0–50, 51–100, 101–150, 151–200, and 201–255 A.U. was examined before and after immobilization. We also sought to determine if further subdividing the histogram into 25 A.U. bands (i.e., 0–25, 26–50, etc.) would be a more sensitive methodological approach. Immobilization resulted in a decrease in the percentage of pixels within the 0–50 A.U. band (-3.11 ± 3.98%), but an increase in the 101–150 A.U. (2.94 ± 2.64%) and 151–200 A.U. (0.93 ± 1.42%) bands. Analyses of variance on the change scores indicated that these differences were large and significant (%EI0-50 vs. %EI101-150: p < .001, d = 1.243); %EI0-50 vs. %EI151-200: p = .043, d = 0.831). The effect size for the %EI51-100 versus %EI101-150 comparison was medium/large (d = 0.762), but not statistically significant (p = .085). Further analysis of the 25 A.U. bands indicated that the percentage of pixels within the 25–50 A.U. band decreased (-2.97 ± 3.64%), whereas the 101–125 (1.62 ± 1.47%) and 126–150 A.U. (1.18 ± 1.07%) bands increased. Comparison of the 50 A.U. and 25 A.U. band methods found that 25 A.U. bands offer little additional insight. Though studies are needed to ascertain the factors that may influence specific bands, changes in EI during muscle disuse are not homogeneous across the pixel histogram. We encourage investigators to think critically about the robustness of data obtained from EI histograms, rather than simply reporting the EImean value, in muscle quality research.

Quantifying the differential functional behavior between the medial and lateral meniscus after posterior meniscus root tears

Meniscus tears of the knee are among the most common orthopedic knee injury. Specifically, tears of the posterior root can result in abnormal meniscal extrusion leading to decreased function and progressive osteoarthritis. Despite contemporary surgical treatments of posterior meniscus root tears, there is a low rate of healing and an incidence of residual meniscus extrusion approaching 30%, illustrating an inability to recapitulate native meniscus function. Here, we characterized the differential functional behavior of the medial and lateral meniscus during axial compression load and dynamic knee motion using a cadaveric model. We hypothesized essential differences in extrusion between the medial and lateral meniscus in response to axial compression and knee range of motion. We found no differences in the amount of meniscus extrusion between the medial and lateral meniscus with a competent posterior root (0.338mm vs. 0.235mm; p-value = 0.181). However, posterior root detachment resulted in a consistently increased meniscus extrusion for the medial meniscus compared to the lateral meniscus (2.233mm vs. 0.4705mm; p-value < 0.0001). Moreover, detachment of the posterior root of the medial meniscus resulted in an increase in extrusion at all angles of knee flexion and was most pronounced (4.00mm ± 1.26mm) at 30-degrees of knee flexion. In contrast, the maximum mean extrusion of the lateral meniscus was 1.65mm ± 0.97mm, occurring in full extension. Furthermore, only the medial meniscus extruded during dynamic knee flexion after posterior root detachment. Given the differential functional behaviors between the medial and lateral meniscus, these findings suggest that posterior root repair requires reducing overall meniscus extrusion and recapitulating the native functional responses specific to each meniscus.

Placement of an anatomic tibial tunnel significantly improves the medial meniscus posterior extrusion at 90° of knee flexion following medial meniscus posterior root pullout repair

PURPOSE

The purpose of this study was to evaluate the influence of tibial tunnel position in pullout repair for a medial meniscus (MM) posterior root tear (MMPRT) on postoperative MM extrusion.

METHODS

Thirty patients (median age 63 years, range 35-72 years) who underwent transtibial pullout repairs for MMPRTs were included. Three-dimensional computed tomography images of the tibial surface were evaluated using a rectangular measurement grid for assessment of tibial tunnel position and MM posterior root attachment. Preoperative and postoperative MM medial extrusion (MMME) and posterior extrusion (MMPE) at 10° and 90° knee flexion were measured using open magnetic resonance imaging.

RESULTS

Tibial tunnel centers were located more anteriorly and more medially than the anatomic center (median distance 5.8 mm, range 0-9.3 mm). The postoperative MMPE at 90° knee flexion was significantly reduced after pullout repair, although there was no significant reduction in MMME or MMPE at 10° knee flexion after surgery. In the correlation analysis of the displacement between the anatomic center to the tibial tunnel center and improvements in MMME, and MMPE at 10° and 90° knee flexion, there was a significant positive correlation between percentage distance and improvement of MMPE at 90° knee flexion.

CONCLUSION

This study demonstrated that the nearer the tibial tunnel position to the anatomic attachment of the MM posterior root, the more effective the reduction in MMPE at 90° knee flexion. Our results emphasize that an anatomic tibial tunnel should be created in the MM posterior root to improve the postoperative MMPE and protect the articular cartilage in a knee flexion position. Placement of an anatomic tibial tunnel significantly improves the MMPE at 90° of knee flexion after MM posterior root pullout repair.

LEVEL OF EVIDENCE

IV.

Intra-substance meniscal changes and their clinical significance: a meta-analysis

The degeneration of radial tie fibres of the central meniscal layer, and thinning of its lamellar layer results in increased intensity signals on magnetic resonance imaging, making it difficult to differentiate from true meniscal tear. This study aimed to assess the rate of encountered MRI grades 1 and 2 intrasubstance meniscal changes, and to set guidelines to report these changes based on predicted clinical outcome. A systematic review approach was employed using search engines, libraries, and databases (Google Scholar, ERIC, PubMed, and Medline) to search for scholarly sources on meniscal lesions and their significance in MRI published between 1 January 2000 and 30 June 2019. It retrieved 2750 abstracts, out of which 2738 were excluded and 13 studies meeting inclusion criteria were meta-analysed. It found an association between intrasubstances meniscal changes and outcomes. It resulted that intrasubstance meniscal changes were preservable through the protective functioning of the meniscus. Other than weight gain, no other significant risk factor of developing true meniscal tears later in life was found. It is important to examine intrasubstance meniscal change when patients suffer from mechanical meniscal symptoms especially in old age.

Multifactorial Determinants of Running Injury Locations in 550 Injured Recreational Runners

PURPOSE

Despite the health benefits of running, the prevalence of running-related injuries (RRI) remains high. The underlying risk factors between these injuries are still not well understood. Therefore, the aim of this study was to compare biomechanical, anthropometric, and demographic injury risk factors between different locations in injured recreational runners.

METHODS

In this retrospective case-control analysis, 550 injured runners (49.6% female) with a medically diagnosed RRI were included. All runners had undergone an instrumented treadmill analysis to determine habitual footstrike pattern, vertical instantaneous load rate, peak vertical ground reaction force (vGRF) and cadence. Injuries were classified by location according to a recent consensus statement. A logistic regression model was used to determine the association between the biomechanical parameters and RRI locations. Because injuries can be associated with age, sex, and body mass index, these variables were also entered into the logistic regression.

RESULTS

Strike pattern and peak vGRF were the only biomechanical variable distinguishing an injury from the group of injuries. A midfoot strike differentiated Achilles tendon injuries (odds ratio [OR], 2.27; 90% confidence interval [CI], 1.17-4.41) and a forefoot strike distinguished posterior lower leg injuries (OR, 2.59; 90% CI, 1.50-4.47) from the rest of the injured group. Peak vGRF was weakly associated with hip injuries (OR, 1.14; 90% CI, 1.05-1.24). Female sex was associated with injuries to the lower leg (OR, 2.65; 90% CI, 1.45-4.87) and hip/groin (OR, 2.22; 90% CI, 1.43-3.45). Male sex was associated with Achilles tendon injuries (OR, 1.923; 90% CI, 1.094-3.378).

CONCLUSIONS

Sex, foot strike pattern, and vGRF were the only factors that distinguished specific injury locations from the remaining injury locations.

Surgical intra- and extra-articular anterior cruciate ligament reconstruction: a meta-analysis

BACKGROUND

It is still controversial whether the combination of anterior cruciate ligament (ACL) reconstruction and extra-articular reconstruction (EAR) have good clinical efficacy. This meta-analysis aims systematically to compare the clinical effectiveness of ACL reconstruction and combined reconstruction.

METHODS

Electronic databases, including Medline/PubMed, Embase and the Cochrane Library, were systematically searched to identify targeted studies. A meta-analysis were performed to pool the outcome estimates of interest, such as the Lysholm, International Knee Documentation Committee (IKDC) and Tegner scores and the results from the KT-1000/2000 arthrometer test, the Lachman test and the pivot shift test.

RESULTS

Twelve studies involving 1146 knees were identified. Compared with single ACL reconstruction, combined reconstruction had better results for a pivot shift of grade 1 (relative ratio [RR] = 0.88, 95% CI: 0.83-0.94) and grade 2 (RR = 0.95, 95% CI: 0.91-0.99) rather than grade 3 (RR = 0.98, 95% CI: 0.90-1.06) and no statistically significant difference for both Lachman grade 1 (RR = 0.96, 95% CI: 0.89-1.05) and grade 2 (RR = 0.96, 95% CI: 0.90-1.03). Combined reconstruction resulted in significant improvements on the instrumented joint laxity test when considering a failure standard of more than 5 mm (a side-to-side arthrometric difference) (RR = 0.94, 95% CI: 0.89-0.98) rather than 3 mm (RR = 0.94, 95% CI: 0.86-1.03). Moreover, combined reconstruction increased the IKDC score at the 12-month (weighted mean difference [WMD] = - 6.38, 95% CI: - 9.66 to - 3.10), 24-month (WMD = - 5.60, 95% CI: - 8.54 to - 2.66) and 36-month follow-ups (WMD = - 4.71, 95% CI: - 7.59 to - 1.83) and the Tegner score at the 36-month follow-up (WMD = - 0.53, 95% CI: - 0.97 to - 0.09), but it did not increase the Lysholm score at the 36-month follow-up (WMD = - 0.84, 95% CI: - 2.02 to 0.34).

CONCLUSION

With the advances in reconstruction techniques, combined reconstructions were found to be effective in improving rotational stability and to lead to good functional scores. However, obviously, the combined reconstruction technique is more time-consuming and requires an additional incision, which is not suitable for all ACL-deficient patients. Therefore, programs should be personalized and customized for the specific situation of each patient.

Etiology of knee pain in elite cyclists: A 14-month consecutive case series

Overuse injuries of the knee are a common cause of missed training and competition days in elite cyclists, however the underlying conditions causing this knee pain are not well defined. We conducted a diagnostic study, investigating a consecutive series of 53 high level cyclists with non-traumatic knee pain over a 14 month period. Demographic data on the participants' cycling specialty and training level was noted. Clinical information concerning knee pain intensity, location and occurrence were collected using a questionnaire. Our results show 7 different overuse injuries were identified. The prepatellar friction syndrome accounted for the majority of these overuse injuries (46%), while medial plica syndrome (15%), biceps femoris tendinopathy (7.5%), patellar tendinopathy (9.4%), infrapatellar plica friction syndrome (7.5%), infrapatellar fat pad impingement (5.7%) and iliotibial band syndrome (3.7%) were other causes of knee pain in these athletes. In contrast to current belief, our results show that instead of patellofemoral cartilage overload, friction related overuse injuries are the most frequent and underestimated cause of knee pain in high level cyclists.

Posterolateral Corner Injury Evolution of Diagnosis and Treatment

Injuries to the posterolateral corner of the knee are rare but significant injuries that occur most commonly in the context of a multiligamentous knee injury. The structures of the posterolateral corner serve as a primary restraint to varus and external rotation and as a secondary restraint to posterior translation. Contemporary reconstructive techniques focus on anatomic restoration of function of the posterolateral corner and excellent long-term results have been demonstrated.

Traumatic injury of the knee extensor mechanism in skeletally immature patients: Outcome and classification

BACKGROUND

The literature is limited on the etiology and outcome of acute traumatic knee extensor mechanism injuries in skeletally immature patients with lack of a reliable classification system.

METHODS

Data on patients who sustained an acute traumatic injury of the knee extensor mechanism were reviewed with a minimum of 12-month follow-up. Functional outcome was evaluated regarding knee active range of motion. Functional outcome was described using the Knee Society Score (KSS). Data were expressed as mean ± standard deviation.

RESULTS

Seventy-two patients with 74 knee extensor mechanism injuries were identified. The age at the time of injury was 13.9 ± 1.9 years. They included 59 injuries with tibial tubercle avulsion fracture, six injuries with patellar tendon avulsion without bone injury, six injuries with combined patellar tendon avulsion with tibial tubercle fracture, two injuries with sleeve fracture, and one injury with quadriceps tendon avulsion. According to our classification, type IB1 injury was the commonest injury (79.7%). The time to return to sports was 5.23 ± 2.98 months. The flexion was 128.7° ± 13.3°. A mean terminal extension lag of 5.6° was detected in three patients (4.1%). The KSS was 94.8 ± 8.1 and the functional outcome was graded excellent in 64 patients (88.9%), good in seven patients (9.7%), and fair in one patient (1.4%).

CONCLUSIONS

Traumatic injuries of the knee extensor mechanism in skeletally immature patients represent a wide variety of injuries including bony injuries in 82.4% of cases reviewed, tendinous injuries in 9.5%, and both bone and tendinous injuries in 8.1%. Our proposed classification system provides a more precise description of the injury pattern.

Return to Sport and Work After High Tibial Osteotomy With Concomitant Medial Meniscal Allograft Transplant

PURPOSE

(1) To examine the timeline of return to sport (RTS) and return to work (RTW) after high tibial osteotomy (HTO) with concomitant medial meniscal allograft transplant (MAT), (2) to evaluate the degree of function on RTS and RTW, and (3) to identify reasons patients do not return to sport- or work-related activity.

METHODS

Patients undergoing HTO plus MAT were reviewed retrospectively at a minimum of 2 years postoperatively. The exclusion criterion was any concomitant procedure except cartilage restoration for focal full-thickness medial femoral condylar defects. Patients completed a subjective sport and work questionnaire, a visual analog scale for pain, the Single Assessment Numeric Evaluation, and a satisfaction questionnaire.

RESULTS

Twenty-two patients (aged 35.1 ± 8.1 years) were included at 9.3 ± 3.7 years postoperatively. Sixteen patients participated in sports within 3 years before surgery, and 14 patients (87.5%) returned to sport by 9.7 ± 3.8 months postoperatively. Only 7 patients (43.8%) returned to their preinjury status. Eighteen patients were employed within 3 years before surgery, and all patients returned to work; however, only 16 patients (88.9%) returned at the same occupational intensity by 3.1 ± 2.4 months. The rates of RTW for light-, medium-, and heavy-intensity occupations were 100%, 75.0%, and 85.7%, respectively, whereas the duration of RTW was 2.1 months, 2.3 months, and 4.8 months, respectively. Of the patients, 20 (90.9%) reported at least 1 complaint postoperatively, with 13 patients (59.1%) returning to the operating room for recurrent symptoms, including 1 patient who received a knee replacement at 7.75 years postoperatively.

CONCLUSIONS

In patients with medial meniscal deficiency and varus deformity, HTO plus MAT provided high rates of RTS (87.5%) and RTW (100%) by 9.7 months and 3.1 months, respectively. It is imperative that clinicians manage expectations because patients may RTS and RTW after HTO plus MAT; however, return to high-intensity activities or occupations may be unlikely or delayed.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The Pediatric "Floating Knee" Injury: A State-of-the-Art Multicenter Study

BACKGROUND

Isolated femoral and tibial fractures are 2 of the top 5 causes of pediatric orthopaedic hospital admission, yet their simultaneous ipsilateral presentation, the "floating knee" injury, remains rare. Historically, treatment consisted of traction and cast immobilization, which resulted in prolonged periods of immobilization, lengthy hospitalizations, and high rates of malunion. As such, previous authors have recommended fixation of at least 1 bone in the setting of a floating knee injury. This strategy, however, has never been evaluated and the outcomes of modern treatment are unknown.

METHODS

We performed a multicenter retrospective review of the records of pediatric patients with ipsilateral femoral and tibial fractures that had been treated at 11 tertiary care level-I pediatric trauma centers from 2004 to 2014. Outcomes and treatment strategies were assessed with standardized means.

RESULTS

Over the study period, 130 floating knees in 129 patients met the inclusion criteria for evaluation. The average patient age was 10.2 years, and 63.1% were male. One-third of the patients presented with open injuries, and 83.8% of injuries were related to vehicular trauma. Simple diaphyseal fractures (OTA/AO 32-A and B femoral fractures and OTA/AO 42-A and B tibial fractures) were most common. Intramedullary fixation (rigid or flexible) was the most common treatment strategy for femoral fractures (69.2%). Tibial fractures were treated most commonly with casting (27.7%), followed by flexible intramedullary nailing (24.6%). The mean duration of hospitalization was 9.7 days. Outcomes were excellent in 66.6% of cases and good in 26.4% of cases.

CONCLUSIONS

Previous literature on pediatric floating knee injuries consisted of small case series that were published prior to the introduction of flexible intramedullary nailing to North America. This multicenter study of a large cohort demonstrates a change in practice pattern from a largely nonoperative treatment strategy to operative fixation of at least the femoral fracture. In the present study, this approach led to good or excellent results in 93.1% of cases and was associated with a short duration of hospitalization.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Major concern in the multiligament-injured knee treatment: A systematic review

PURPOSE

The purpose of this systematic review was to address the treatment of multiligament knee injuries in three major aspects, specifically (1) surgical versus nonoperative treatment, (2) repair versus reconstruction of injured ligamentous structures, and (3) early versus late surgery of damaged ligaments.

METHODS

Two independent reviewers performed a search on PubMed from 1966 to March 2016 using Levy's review as a starting-point, and the same terms "knee dislocation," "multiple ligament-injured knee," and "multiligament knee reconstruction." Study inclusion criteria were (1) levels I to IV evidence, (2) "multiligament" defined as disruption of at least 2 of the 4 major knee ligaments, (3) measures of functional and clinical outcomes, and (4) minimum of 12 months' follow-up, with a mean of at least 24 months.

RESULTS

Two high-level studies compared surgical treatment with nonoperative treatment. There was a higher Lyshom scores (85 v 67) in surgically treated patients, as well as higher excellent/good IKDC scores (69% v 64%) and return to sport (41% v 18%). There were four studies comparing repair with reconstruction of damaged structures, with similar mean Lysholm scores (84 v 84) and excellent/good IKDC scores (63% v 63%). Nevertheless, repair of the posterolateral corner had a higher failure rate (39% v 8%) and a lower return to sport activities (25% v 51%). Similarly, repair of the cruciates achieved decreased stability and range of motion. There were six studies comparing early surgery (within 3 weeks) with delayed surgery. Early treatment resulted in higher mean Lysholm scores (89 v 82) and a higher percentage of excellent/good IKDC scores (57% v 41%), as well as higher mean ROM (129° v 124°).

CONCLUSIONS

Our review suggests that the best treatment does not exist, but better functional and clinical outcomes have been achieved with reconstruction rather than repair. Surgery must be performed within the first three weeks. Delayed ACL reconstruction allows to reduce arthrofibrosis rate.

A comparison of muscle activation and knee mechanics during gait between patients with non-traumatic and post-traumatic knee osteoarthritis

OBJECTIVE

The objective was to compare muscle activation and knee mechanics during gait between participants with non-traumatic knee osteoarthritis (OA), post-traumatic knee OA, and healthy adults.

DESIGN

Participants with non-traumatic knee OA (n = 22), post-traumatic knee OA (n = 19), and healthy adults (n = 22) completed gait trials for this observational, cross-sectional study. Post-traumatic OA group had a history of traumatic anterior cruciate ligament (ACL) rupture. Surface electromyography (EMG) measured activation of seven lower extremity muscles. Motion capture cameras and force plates measured motion and force data. Principal component analysis (PCA) determined waveform characteristics (principal components) from EMG, knee angle, and knee external moment waveforms. Analysis of variance (ANOVA) examined group differences in principal component scores (PC-scores). Regression analyses examined if a variable that coded for OA group could predict PC-scores after accounting for disease severity, alignment, and lateral OA.

RESULTS

There was lower gastrocnemius EMG amplitudes (P < 0.01; ANOVA) in the post-traumatic OA group compared to healthy group. Non-traumatic OA group had higher vastus lateralis, vastus medialis, and rectus femoris EMG compared to post-traumatic OA group (P = 0.01 to 0.04) in regression analyses. Also, non-traumatic OA group had higher and prolonged lateral hamstring EMG compared to healthy (P = 0.03; ANOVA) and post-traumatic OA (P = 0.04; regression) groups respectively. The non-traumatic OA group had lower knee extension (P < 0.05) and medial rotation (P < 0.05) moments than post-traumatic and healthy groups.

CONCLUSIONS

Muscle activation and knee mechanics differed between participants with non-traumatic and post-traumatic knee OA and healthy adults. These OA subtypes had differences in disease characteristics that may impact disease progression.

Primary Posterior Cruciate Ligament Repair With The Novel Suture Tape Augmentation Technique

BACKGROUND

A posterior cruciate ligament (PCL) rupture is less common than an anterior cruciate ligament (ACL) rupture. PCL reconstruction remains controversial with variable outcomes and problems. The encouraging results of the novel ACL repair techniques led to renewed interest in PCL repair. Primary arthroscopic PCL repair has been rarely discussed and literature is scarce. To the best of our knowledge, no PCL repair patient outcome has been reported with one of the novel PCL repair techniques. We present the first case report of two patients who have been treated with the novel PCL repair technique, the suture tape augmentation technique.

CASE DESCRIPTION

Two patients who underwent primary PCL repair after an acute PCL rupture with a two-year follow up are presented. Patients were evaluated according to the Lysholm scale, the International Knee Documentation Committee (IKDC), and the Tegner activity scale. Follow up also included objective physical examinations-knee function and posterior drawer test using a rolimeter-and magnetic resonance imaging (MRI). Physical examinations were performed at three months, six months, one year, and two years after surgery.

OUTCOMES

At two-year follow up, both patients had a full range of motion and experienced no pain, nor swelling. IKDC scores were 83% (good) and 100% (excellent), Lysholm scores were 99 and 100 two years after surgery. At three months postoperative, the Tegner activity scale equaled the preinjury Tegner activity scale. One patient was horseback riding within three months. There were some increased posterior translation differences after two years-+2 and +3mm-compared with six weeks postoperative. MRI showed a healed PCL in both cases.

DISCUSSION

PCL repair could be a promising treatment option for acute PCL ruptures. Advantages of this technique are the retaining of the natural proprioceptive capacities due to preserving native PCL fibers, the surgical technique is less invasive compared to a reconstruction, and no donor graft morbidity is expected as no graft is needed.

CONCLUSION

In these two cases, good subjective and objective results are demonstrated after PCL repair using the novel suture tape augmentation technique. MRI confirmed the healing of the PCL. Although this is a small case series, as PCL ruptures are less common compared to ACL ruptures, it is a stepping-stone for further PCL repair research.

Real-Time Three-Dimensional Knee Moment Estimation in Knee Osteoarthritis: Toward Biodynamic Knee Osteoarthritis Evaluation and Training

We investigated differences in knee kinetic variables (external knee adduction, flexion, internal rotation moments, and impulses) between patients with knee osteoarthritis (KOA) and healthy controls during stepping on a custom elliptical trainer; and searched knee kinetic variable candidates for real-time biofeedback and for complementing diagnosis/evaluation on the elliptical trainer based on the knee kinetic variables' associations with the knee injury and osteoarthritis outcome score (KOOS). Furthermore, we explored potential gait re-training strategies on the elliptical trainer by investigating the knee kinetic variables' associations with 3-D ankle angles. The knee kinetic variables and ankle angles were determined in real-time in a patient group of 10 patients with KOA and an age-and sex-matched control group of 10 healthy subjects. The mean peak external knee adduction moment of the patient group was 47% higher than that of the control group. The KOOS-Sports and Recreational Activities and KOOS-Pain scores were found to be significantly associated with the knee kinetic variables. All the ankle angles were associated with the knee kinetic variables. The findings support the use of the knee kinetic variables on the elliptical trainer to complement KOA diagnosis quantitatively and provide potential real-time KOA gait re-training strategies/guides.

Combined avulsion fracture of the tibial tubercle and patellar tendon rupture in adolescents: a case report

Simultaneous occurrence of tibial tubercle fracture and patellar tendon avulsion is an extremely rare condition. However, they have become more frequent due to increased participation in sports at a younger age. Diagnosis is not always straightforward, and treatment consists of open reduction and internal fixation. Only a few case reports of such injuries were reported in the literature with limited information according to diagnoses, treatment, and outcome in adolescents.

An ICA-EBM-Based sEMG Classifier for Recognizing Lower Limb Movements in Individuals With and Without Knee Pathology

Surface electromyography (sEMG) data acquired during lower limb movements has the potential for investigating knee pathology. Nevertheless, a major challenge encountered with sEMG signals generated by lower limb movements is the intersubject variability, because the signals recorded from the leg or thigh muscles are contingent on the characteristics of a subject such as gait activity and muscle structure. In order to cope with this difficulty, we have designed a three-step classification scheme. First, the multichannel sEMG is decomposed into activities of the underlying sources by means of independent component analysis via entropy bound minimization. Next, a set of time-domain features, which would best discriminate various movements, are extracted from the source estimates. Finally, the feature selection is performed with the help of the Fisher score and a scree-plot-based statistical technique, prior to feeding the dimension-reduced features to the linear discriminant analysis. The investigation involves 11 healthy subjects and 11 individuals with knee pathology performing three different lower limb movements, namely, walking, sitting, and standing, which yielded an average classification accuracy of 96.1% and 86.2%, respectively. While the outcome of this study per se is very encouraging, with suitable improvement, the clinical application of such an sEMG-based pattern recognition system that distinguishes healthy and knee pathological subjects would be an attractive consequence.

T2-relaxation time of cartilage repair tissue is associated with bone remodeling after spongiosa-augmented matrix-associated autologous chondrocyte implantation

OBJECTIVE

To investigate whether T2 relaxation time measurements of cartilage repair tissue and structural changes of the knee joint are associated with subchondral bone architecture after spongiosa-augmented matrix-associated autologous chondrocyte implantation (MACI).

DESIGN

Both knees of 25 patients (25.5 ± 7.8y; 10 women) were examined preoperatively and 2.7 years after unilateral spongiosa-augmented MACI with 3T magnetic resonance (MR) imaging. Cartilage composition was assessed using T2 relaxation time measurements, subchondral trabecular bone microstructure was quantified using a 3D phase-cycled balanced steady state free-precision sequence. Structural knee joint changes were assessed using the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was used for the postoperative description of the area that underwent MACI. Correlations were assessed using Spearman's rank correlation coefficients.

RESULTS

Hypertrophy of the cartilage repair tissue was found in 2 of 25 patients, both after a MACI procedure at the patella, 21 patients showed congruent filling. In subchondral bone of the cartilage repair compartment, apparent trabecular thickness was significantly higher in compartments with elevated cartilage T2 (n = 17; 0.37 ± 0.05 mm) compared to those showing no difference in cartilage T2 compared to the same compartment in the contralateral knee (n = 8; 0.27 ± 0.05 mm; P = 0.042). Significant correlations were found between the overall progression of WORMS and the ipsilateral vs contralateral ratio of average trabecular thickness (r = 0.48, P = 0.031) and bone fraction (r = 0.57, P = 0.007).

CONCLUSIONS

After spongiosa-augmented MACI, T2 values of cartilage repair tissue and structural knee joint changes correlated with the quality of the underlying trabecular bone.

Tibiofemoral joint contact forces increase with load magnitude and walking speed but remain almost unchanged with different types of carried load

Musculoskeletal injuries (MSI) in the military reduce soldier capability and impose substantial costs. Characterizing biomechanical surrogates of MSI during commonly performed military tasks (e.g., load carriage) is necessary for evaluating the effectiveness of possible interventions to reduce MSI risk. This study determined the effects of body-borne load distribution, load magnitude, and walking speed on tibiofemoral contact forces. Twenty-one Australian Army Reserve soldiers completed a treadmill walking protocol in an unloaded condition and wearing four armor types (standard-issue and three prototypes) with two load configurations (15 and 30 kg) for a total of 8 armor x load ensembles. In each ensemble, participants completed a 5-minute warm-up, and then walked for 10 minutes at both moderate (1.53 m⋅s^-1) and fast (1.81 m⋅s^-1) speeds. During treadmill walking, three-dimensional kinematics, ground reaction forces, and muscle activity from nine lower-limb muscles were collected in the final minute of each speed. These data were used as inputs into a neuromusculoskeletal model, which estimated medial, lateral and total tibiofemoral contact forces. Repeated measures analyses of variance revealed no differences for any variables between armor types, but peak medial compartment contact forces increased when progressing from moderate to fast walking and with increased load (p<0.001). Acute exposure to load carriage increased estimated tibiofemoral contact forces 10.1 and 19.9% with 15 and 30kg of carried load, respectively, compared to unloaded walking. These results suggest that soldiers carrying loads in excess of 15 kg for prolonged periods could be at greater risk of knee MSI than those with less exposure.

A Biomechanical Study of an Alternative Internal Fixation Method for Transverse Patella Fractures

Pain and reoperation after fixation using tension band wiring and K-wires is not uncommon. A novel hook plate was designed to improve the treatment of patella fractures. The aim of this study was to compare the stability of the hook plate with that of tension band wiring and K-wires in a simulated patellar transverse fracture model (AO/OTA classification 34-C1.1). The authors tested 16 embalmed cadaver knee joints fixed with the hook plate and tension band wiring and K-wires under cyclic loading. Specimens underwent 100 cycles extending the knee joint from 90° of flexion to full extension at a velocity of 50 mm/min. The fracture gap was measured after the initial and last cycles. Data were assessed statistically using the t test, with significance set as P<.05. The fatigue test showed that the fracture gap after 100 cycles was 2.97±1.39 mm using tension band wiring and K-wires and 1.53±0.93 mm for the hook plate (P=.029). Six of 8 specimens in the tension band wiring and K-wires group met the failure criterion of fracture gap greater than 2 mm vs 1 in the hook plate group (P=.041). From a biomechanical point of view, the hook plate is a valid alternative to tension band wiring and K-wires for fixing patella transverse fractures. Compared with tension band wiring and K-wires, the hook plate may have superior ability in sustaining a reduced transverse patella fracture. [Orthopedics. 2018; 41(5):e643-e648.].

Variables affecting functional outcome in floating knee injuries

BACKGROUND

The surgical outcome of floating knee injuries is difficult to predict. The high-velocity nature of the injury, complex fracture pattern and associated soft tissue/visceral injuries may have some impact on the functional outcome. The present study evaluates the variables affecting the clinical and radiological outcomes of floating knee injuries.

MATERIALS AND METHODS

The clinical, radiological and functional outcome (Karlstrom and Olegrud criteria) of 89 patients with 90 floating knee injuries were evaluated at the end of one year who were managed in our level 1 trauma center between January 2013 and December 2016. The details of the injury, fracture pattern, management and complications were collected retrospectively from their records.

RESULTS

There were 81 (91.1%) males and 8 (8.9%) females with mean age of 34.34 ± 12.28 years. The mean time for tibia and femur union was 9.52 (±6.6) and 10.5 (±7.37) months. There was significant delay (p < 0.005) in time taken for union in segmental femur fractures (14.3 ± 9.6 months) compared to nonsegmental femur fractures (8.68 ± 5.18 months). Such significant difference in time taken for union was not seen in tibial segmental (10.6 ± 4.62 months) and nonsegmental fractures (9.05 ± 7.27 months). As per the Karlstrom and Olegrud criteria, there were 22 (24.4%) excellent, 26 (28.9%) good, 24 (26.7%) fair and 11 (12.2%) poor outcome. There were 15 patients with malunited tibia, 6 with malunited femur, 10 with limb length discrepancy and 39 with knee stiffness. 28 (33.3%) patients underwent major additional procedures such as bone grafting, re-fixation or bone transport or tendon transfer. It was observed that open tibia fracture, segmental fracture, intra-articular fracture, additional surgical procedures, initial external-fixator (ex-fix) application were significantly associated with development of knee stiffness, limb shortening, malalignment and unsatisfactory (Karlstrom and Olegrud fair to poor) functional outcome.

CONCLUSION

Open tibial fractures, segmental fractures, intraarticular involvement, additional surgical procedures and initial external fixator application are the poor prognostic indicators of floating knee injuries.

Epidemiology and outcomes of traumatic knee dislocations: Isolated vs multi-trauma injuries

BACKGROUND AND PURPOSE

Traumatic dislocation of the knee (TKD) is a rare injury, accounting for approximately 0.02% of orthopaedic injuries. They are a challenging entity for orthopaedic surgeons to manage, and can have devastating consequences. The aim of this study was to describe the epidemiology of traumatic knee dislocations (TKD'S) and contrast the incidence of neurovascular injury between isolated and multi-trauma dislocations as well as key patient reported outcomes achieved between these groups.

MATERIAL AND METHODS

Patients who had a traumatic disruption of the tibiofemoral articulation between March 1 2007 and February 31, 2015 were identified from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Data was cross-checked with medical records and radiological reports to confirm true multi-ligamentous dislocation. VOTOR collects information pertaining to orthopaedic injuries, treatment, complications and outcomes from four adult hospitals in Victoria, Australia, including the major trauma centers. Patient-reported outcomes are collected by VOTOR at 12 months post-injury including the EQ-5D-3L (EQ-5D) and Glasgow Extended Outcome Scores (GOS-E) and return to work status. Patient reported functional and quality of life outcomes at 12 months after injury were analysed.

RESULTS

A cohort of 88 patients were identified that fit the inclusion criteria for the study, and at 12 months post-injury there was data available for 80 patients (90.9%). There were 38 (42.9%) patients who experienced an isolated traumatic knee dislocation and 52 (57.1%) who experienced a traumatic knee dislocation in association with another injury. Of the 88 patients identified as eligible for the study, two had bilateral knee dislocations, hence there were 90 multi-ligamentous knee injuries. Those who were injured at a higher velocity were more likely to have additional injuries. Dislocations that occurred at a lower velocity were shown to have better overall outcomes, as did dislocations that occurred in isolation.

CONCLUSIONS

Traumatic knee dislocations that occur in isolation typically result in better outcomes than those that occur with associated injuries. TKD's are a rare but severe injury that requires further research in order for functional outcomes to be optimized.

Acoustical Emission Analysis by Unsupervised Graph Mining: A Novel Biomarker of Knee Health Status

OBJECTIVE

To study knee acoustical emission patterns in subjects with acute knee injury immediately following injury and several months after surgery and rehabilitation.

METHODS

We employed an unsupervised graph mining algorithm to visualize heterogeneity of the high-dimensional acoustical emission data, and then to derive a quantitative metric capturing this heterogeneity-the graph community factor (GCF). A total of 42 subjects participated in the studies. Measurements were taken once each from 33 healthy subjects with no known previous knee injury, and twice each from 9 subjects with unilateral knee injury: first, within seven days of the injury, and second, 4-6 months after surgery when the subjects were determined to start functional activities. Acoustical signals were processed to extract time and frequency domain features from multiple time windows of the recordings from both knees, and k-nearest neighbor graphs were then constructed based on these features.

RESULTS

The GCF calculated from these graphs was found to be 18.5 ± 3.5 for healthy subjects, 24.8 ± 4.4 (p = 0.01) for recently injured, and 16.5 ± 4.7 (p = 0.01) at 4-6 months recovery from surgery.

CONCLUSION

The objective GCF scores changes were consistent with a medical professional's subjective evaluations and subjective functional scores of knee recovery.

SIGNIFICANCE

Unsupervised graph mining to extract GCF from knee acoustical emissions provides a novel, objective, and quantitative biomarker of knee injury and recovery that can be incorporated with a wearable joint health system for use outside of clinical settings, and austere/under resourced conditions, to aid treatment/therapy.

Anterior cruciate ligament graft fixation first in anterior and posterior cruciate ligament reconstruction best restores knee kinematics

PURPOSE

To evaluate the effect of different graft fixation sequences in one-stage anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction on (1) knee biomechanics and (2) tibiofemoral alignment.

METHODS

Twelve porcine knees were used in this study. Five fixation sequences were performed (angle indicating knee flexion): (a) PCL at 30° and ACL at 30°, (b) PCL at 90° and ACL at 30°, (c) ACL at 30° and PCL at 30°, (d) ACL at 30° and PCL at 90°, and (e) ACL and PCL simultaneous fixation at 30°. Anterior and posterior tibial translation was measured under an 89 N load. A 3-D digitizer was used to measure the change in anteroposterior (AP) tibiofemoral position.

RESULTS

None of the graft fixation sequences restored the AP laxity of the intact knee, and there are minimal differences in the in situ tissue forces in the ACL and PCL grafts. The reconstructions with fixation of the PCL graft first resulted in a significantly larger change in AP tibiofemoral position from the intact knee at 60° and 90° of knee flexion than the reconstructions with fixation of the ACL graft first (p < 0.05).

CONCLUSION

Fixation of the ACL graft at 30° of knee flexion followed by fixation of the PCL graft can best restore the tibiofemoral position of the intact knee. This study has clinical relevance in regard to the effect of graft fixation sequence on the position of the tibia relative to the femur in one-stage ACL and PCL reconstruction.

A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study Evaluating Meniscal Healing, Clinical Outcomes, and Safety in Patients Undergoing Meniscal Repair of Unstable, Complete Vertical Meniscal Tears (Bucket Handle) Augmented with Platelet-Rich Plasma

OBJECTIVE

The present study aimed to investigate the effectiveness and safety of platelet-rich plasma (PRP) application in arthroscopic repair of complete vertical tear of meniscus located in the red-white zone.

METHODS

This single center, prospective, randomized, double-blind, placebo-controlled, parallel-arm study included 37 patients with complete vertical meniscus tears. Patients received an intrarepair site injection of either PRP or sterile 0.9% saline during an index arthroscopy. The primary endpoint was the rate of meniscus healing in the two groups. The secondary endpoints were changes in the International Knee Documentation Committee (IKDC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and analog scale (VAS) in the two groups at 42 months.

RESULTS

After 18 weeks, the meniscus healing rate was significantly higher in the PRP-treated group than in the control group (85% versus 47%, P = 0.048). Functional outcomes were significantly better 42 months after treatment than at baseline in both groups. The IKDC score, WOMAC, and KOOS were significantly better in the PRP-treated group than in the control group. No adverse events were reported during the study period.

CONCLUSIONS

The findings of this study indicate that PRP augmentation in meniscus repair results in improvements in both meniscus healing and functional outcome.

Protective Knee Braces and the Biomechanics of the Half-Squat Parachute Landing

INTRODUCTION

Knee injuries are common among paratroopers and skydivers during landing maneuvers. The aim of this study was to investigate the effects of dropping height and the use of protective knee braces on parachute landing biomechanics.

METHODS

The study cohort consisted of 30 male elite paratroopers with formal parachute landing training and more than 2 yr of parachute jumping experience. Each participant was instructed to jump off a platform at two different heights (40 and 80 cm, respectively) and land on force plates in a half-squat posture. All participants tested three different knee brace conditions (no-brace, elastic brace, and semi-rigid brace) at each height.

RESULTS

With an increase in dropping height, peak vertical ground reaction forces (GRF), peak flexion angle, peak flexion angular displacement, peak abduction angle, peak abduction angular displacement, peak extorsion angle, and peak extorsion angular displacement of the knee joint all increased. As compared without the use of a brace, use of an elastic or semi-rigid knee brace significantly reduced peak flexion angle, peak flexion angular displacement, peak abduction angular displacement, and peak extorsion angle, while there were no significant differences in peak vertical GRF or peak extorsion angular displacement. The semi-rigid brace provided the greatest restriction against peak abduction angle (3-6°).

DISCUSSION

The elastic and semi-rigid knee braces both effectively restricted motion stability of the knee joint in the sagittal and coronal planes. The semi-rigid brace had a more marked effect, although the comfort of this device should be improved.Wu D, Zheng C, Wu J, Wang L, Wei X, Wang L. Protective knee braces and the biomechanics of the half-squat parachute landing. Aerosp Med Hum Perform. 2018; 89(1):26-31.

An Elderly Man with a Swollen Knee,Significant Ecchymosis, and Minimal Knee Pain

A 72-year-old man presents with left knee pain and swelling over several days. The pain and swelling started after he felt a "pop" when bending to pick up an object off the floor. His past medical history is significant for type 2 diabetes mellitus. Physical exam revealed significant ecchymosis on the anterolateral aspect of the thigh. There was a minimal amount pain upon knee flexion.

Diffusion tensor imaging of articular cartilage at 3T correlates with histology and biomechanics in a mechanical injury model

PURPOSE

We establish a mechanical injury model for articular cartilage to assess the sensitivity of diffusion tensor imaging (DTI) in detecting cartilage damage early in time. Mechanical injury provides a more realistic model of cartilage degradation compared with commonly used enzymatic degradation.

METHODS

Nine cartilage-on-bone samples were obtained from patients undergoing knee replacement. The 3 Tesla DTI (0.18 × 0.18 × 1 mm3 ) was performed before, 1 week, and 2 weeks after (zero, mild, and severe) injury, with a clinical radial spin-echo DTI (RAISED) sequence used in our hospital. We performed stress-relaxation tests and used a quasilinear-viscoelastic (QLV) model to characterize cartilage mechanical properties. Serial histology sections were dyed with Safranin-O and given an OARSI grade. We then correlated the changes in DTI parameters with the changes in QLV-parameters and OARSI grades.

RESULTS

After severe injury the mean diffusivity increased after 1 and 2 weeks, whereas the fractional anisotropy decreased after 2 weeks (P < 0.05). The QLV-parameters and OARSI grades of the severe injury group differed from the baseline with statistical significance. The changes in mean diffusivity across all the samples correlated with the changes in the OARSI grade (r = 0.72) and QLV-parameters (r = -0.75).

CONCLUSION

DTI is sensitive in tracking early changes after mechanical injury, and its changes correlate with changes in biomechanics and histology. Magn Reson Med 78:69-78, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Outcome of low profile mesh plate in management of comminuted displaced fracture patella

PURPOSE

To assess the clinical results of using mesh plate in management of displaced comminuted fracture patella.

PATIENTS AND METHODS

Between January 2014 and October 2015, nine patients with closed displaced comminuted fracture patella were fixed using mesh plate and 2mm mini screws.

RESULTS

All fractures united after an average of 10 weeks. At final follow-up of an average 19.6 months, average postoperative Lysholm score was 89.1±4.9, and average Postoperative Böstman scale was 27.2±3.1. No hardware related complications were recorded.

CONCLUSION

Low profile mesh plate is a good option in management of comminuted fracture patella with good clinical outcome. This new surgical technique may be particularly useful in comminuted fractures when patellectomy would otherwise be considered.

Biomechanical Evaluation of a Novel Suture Augment in Patella Fixation

Patella fractures, although uncommon in the context of corresponding long bone fractures, carry a disproportionately high degree of morbidity, and are often challenging to treat. As such, this study sought to evaluate the efficacy of a Krackow suture augment when compared to standard tension band fixation and cerclage suture augment in patella fracture repair. Cadaveric patella extensor mechanisms were used for biomechanical testing. Specimens were divided among 3 groups, each with a different repair technique: modified anterior tension band (MATB), MATB plus cerclage suture, and MATB plus Krackow suture. Specimens were biomechanically tested in both cyclic and maximum load settings. Mean displacement and load-to-failure forces were measured for cyclic and maximum load testing, respectively. Data was then analyzed with both one-way analysis of variance and independent t-testing. Both augmentation techniques showed improved strength in both cyclic and maximum load testing, with the Krackow suture augment showing the greatest strength. In cyclic testing, cerclage augment showed a 30% decrease in mean displacement while Krackow suture augment showed a 40% decrease when compared to the MATB repair group. Likewise, in maximum load testing, cerclage repair showed a 5% increase and Krackow a 14% increase in load-to-failure force when compared to MATB. Likely due to small sample size, the increases in repair strength did not reach statistical significance. This study provides support for the use of a Krackow suture augment in patella fracture repair, and we suggest this technique may be most useful in the setting of poor bone quality where conventional repair techniques are limited. Although failing to reach statistical significance, these results are encouraging and warrant further investigation in both biomechanical and clinical settings.

Patellofemoral Pain: An Enigma Explained by Homeostasis and Common Sense

We present a rational, scientific, low-risk approach to patellofemoral pain (anterior knee pain) based on an understanding of tissue homeostasis. Loss of tissue homeostasis from overload and/or injury produces pain. Bone overload and synovial inflammation are common sources of such pain. Chondromalacia and malalignment are findings that almost always do not need to be "corrected" to relieve pain. Patience and persistence in nonoperative care results in consistent success. Surgery should be rare and done only after extensive nonoperative management and in the setting of clearly defined pathology. Rational surgical treatment is explained in the context of restoring tissue homeostasis to relieve pain.

Wearable Vector Electrical Bioimpedance System to Assess Knee Joint Health

OBJECTIVE

We designed and validated a portable electrical bioimpedance (EBI) system to quantify knee joint health.

METHODS

Five separate experiments were performed to demonstrate the: 1) ability of the EBI system to assess knee injury and recovery; 2) interday variability of knee EBI measurements; 3) sensitivity of the system to small changes in interstitial fluid volume; 4) reducing the error of EBI measurements using acceleration signals; and 5) use of the system with dry electrodes integrated to a wearable knee wrap.

RESULTS

1) The absolute difference in resistance ( R) and reactance (X) from the left to the right knee was able to distinguish injured and healthy knees (p < 0.05); the absolute difference in R decreased significantly (p < 0.05) in injured subjects following rehabilitation. 2) The average interday variability (standard deviation) of the absolute difference in knee R was 2.5 Ω and for X was 1.2 Ω. 3) Local heating/cooling resulted in a significant decrease/increase in knee R (p < 0.01). 4) The proposed subject position detection algorithm achieved 97.4% leave-one subject out cross-validated accuracy and 98.2% precision in detecting when the subject is in the correct position to take measurements. 5) Linear regression between the knee R and X measured using the wet electrodes and the designed wearable knee wrap were highly correlated ( R² = 0.8 and 0.9, respectively).

CONCLUSION

This study demonstrates the use of wearable EBI measurements in monitoring knee joint health.

SIGNIFICANCE

The proposed wearable system has the potential for assessing knee joint health outside the clinic/lab and help guide rehabilitation.

Intra-articular injections of HYADD4-G in male professional soccer players with traumatic or degenerative knee chondropathy. A pilot, prospective study

BACKGROUND

Knee injuries are very common in some sports and particularly in soccer due to the highly repetitive loading of the mechanical stress involved in this practice. Knee-joint injuries account for 40% of all different kinds of lesions. Traumatic or degenerative patellofemoral or tibialfemoral chondropaties of knee cause disabling symptoms, joint pain and/or dysfunctions. The aim of the study was to evaluate the effects of HYADD4-G, a hydrogel based on a hyaluronic acid derivative, in professional soccer players affected by traumatic or degenerative knee chondropathy.

METHODS

Thirty male professional soccer players participants in the Italian League 2014-2015, affected by traumatic or degenerative knee patellofemoral (N.=12) or tibiofemoral (N.=18) chondropathy assessed through MRI and/or arthroscopy of knee joints and the ICRS staging (International Cartilage Repair Society ≤3a), were enrolled in this pilot prospective study. Patients underwent 2 intra-articular (IA) injections of HYADD4-G (3 mL of 8 mg/mL) at one week interval. Patients were prospectively evaluated at baseline and then at 1, 3 and 6 months after the treatment by the Osteoarthritis Outcome Score (KOOS) Score (main outcome) and by the Visual Analog Scale (VAS) to evaluate pain.

RESULTS

A significant improvement in all clinical endpoints from pretreatment to different times of evaluation was found in all patients. ANOVA with repeated measure using the SPSS has showed significantly better results in term of KOOS and VAS scores at 1, 3 and 6 months compared to the pre-injection value (P<0.05).

CONCLUSIONS

IA HYADD4-G is highly effective to improve resting and walking pain in professional male soccer players with traumatic or degenerative knee chondropathy.

Primary Cartilage Lesions of the Knee Joint in Young Male Adults. Overweight as a Predisposing Factor. An Arthroscopic Study

Background and Aims:

This study was undertaken to evaluate the relationship between overweight and severity of arthroscopically confirmed primary cartilage lesions of the knee.

Material and Methods:

The hospital records of 88 young male adults (98 knees), who underwent arthroscopy of the knee and were diagnosed of primary cartilage lesion during 1997–98, were reviewed. The depth of the lesions was graded according to Beguin and Locker classification.

Results:

73.5 % of the lesions were patellar and 12.0 % in the medial condyle of the femur. 74.5 % of the patients had superficial (grade I—II) and 25.5 % deep (grade III—IV) lesions. Patients with deep lesions had a significantly higher body mass index (BMI 25.3 vs. 22.9, p < 0.001) and they were older (20.8 vs. 19.7 years, p = 0.023) than other patients. Similarly, patients with overweight (BMI ≥ 25.0) had significantly more often deep lesions than other patients (50 % vs. 10.4 %, p < 0.001).

Conclusions:

These results suggest, that overweight may predispose young patients to more severe cartilage lesions independent of other etiologic factors, and support the hypothesis of the cumulative effect of overweight on cartilage injuries during early adult life.

Intra-articular tibial plateau fracture characteristics according to the "Ten segment classification"

BACKGROUND

Currently existing classifications of tibial plateau fractures do not help to guide surgical strategy. Recently, a segment-based mapping of the tibial plateau has been introduced in order to address fractures with a fracture-specific surgical approach. The goal of the present study was to analyze incidence and fracture specifics according to a new 10-segment classification of the tibial plateau.

METHODS

A total of 242 patients with 246 affected knees were included (124 females, 118 males, mean age 51.9±16.1years). Fractures were classified according to the OTA/AO classification. Fracture pattern was analyzed with respect to a 10-segment classification based on CT imaging of the proximal tibial plateau 3cm below the articular surface.

RESULTS

161 Patients suffered an OTA/AO type 41-B and 85 patients an OTA/AO type 41-C tibial plateau fracture. Females had an almost seven times higher risk to suffer a fracture due to low-energy trauma (OR 6.91, 95% CI (3.52, 13.54), p<0.001) than males. In 34% of the patients with affection of the medial tibial plateau, a fracture comminution, primarily due to low-energy trauma (p<0.001), was observed. In type B fractures, the postero-latero-lateral (65.2%), the antero-latero-lateral (64.6%) and the antero-latero-central (60.9%) segment were most frequently affected. Every second type C fracture showed an unique fracture line and zone of comminution. The tibial spine was typically involved (89.4%). A typical fracture pattern of high-energy trauma demonstrated a zone of comminution of the lateral plateau and a split fracture in the medial plateau. The most frequently affected segments were the postero-latero-central (85.9%), postero-central (84.7%), and antero-latero-central (78.8%) segment.

CONCLUSION

Posterior segments were the most frequently affected in OTA/AO type B and C fractures. Acknowledging the restricted visibility of posterior segments, whose reduction and fixation is crucial for long-term success, our findings implicate the use of posterior approaches more often in the treatment of tibial plateau fractures. Also, low-energy trauma was identified as an important cause for tibial plateau fractures.

A Meta-Analysis to Determine if Lower Extremity Muscle Strengthening Should Be Included in Military Knee Overuse Injury-Prevention Programs

CONTEXT

 Knee overuse injuries are the most common musculoskeletal complaints in military trainees and are common in active-duty warfighters. Muscle strengthening is usually recommended; however, research is conflicting in this area, which makes it difficult to develop effective screening, prevention, and training interventions for warfighters.

OBJECTIVE

 To determine if lower extremity muscular weakness contributes to knee overuse injuries and identify specific muscular involvement.

DATA SOURCES

 We searched MEDLINE, PubMed, Web of Science, SPORTDiscus, CINAHL, and Military & Government Collection and reference lists of relevant articles published between January 1, 2000, and January 1, 2013.

STUDY SELECTION

 For inclusion, requirements were uninjured and injured groups; provision of the sample size, means, and standard deviations for all groups; identification of the specific muscles assessed; and clearly defined knee injury.

DATA EXTRACTION

 Sample size, sex, and muscle strength means and standard deviations.

DATA SYNTHESIS

 Twenty-five studies met these criteria. We used the Scottish Intercollegiate Guidelines Network algorithm to determine the appropriate tool for appraising article quality. Unweighted random-effects model meta-analyses were conducted. Separate meta-analyses were performed for the moderators of strength measurement scale (absolute or normalized muscle strength), muscle group, and sex. A weighted random-effects model with a Hedges g effect metric and 95% confidence intervals were used for comparison across studies.

CONCLUSIONS

 Our meta-analysis suggests that individuals with symptoms of a knee overuse injury have lower absolute and normalized hip muscle strength. Specifically, they had lower absolute hip external-rotator, knee-extensor, and knee-flexor strength, as well as lower normalized hip external-rotator, hip-extensor, and hip-abductor strength, compared with asymptomatic control participants. The findings suggest a possible link between lower hip and thigh strength and knee overuse injuries. Further research is needed to determine if weakness is a cause or a result of knee overuse injuries before screening and intervention can be developed for at-risk warfighters.

Evidence of patellar tendon buckling during passive knee extension

PURPOSE

The purpose of this study was to investigate and describe buckling of the patellar tendon.

METHODS

Healthy young adults (28±4years, 10F/10M) underwent passive knee flexion/extension during the simultaneous measurement of knee angle and collection of cine ultrasound from the patellar tendon. Patellar tendon buckling was observed visually in ultrasound images, and the corresponding knee angle at which evidence of buckling disappeared was identified.

RESULTS

All subjects showed evidence of distal buckling which occurred on average at 23±8° flexion. Proximal buckling was only observed in fourteen subjects (10F/4M) at an average of 15±8°. Buckling patterns varied between subjects, but with high within-subject consistency. Buckling magnitude increased with age (p=0.03) and decreased with more weekly exercise (p=0.02).

DISCUSSION

The patellar tendon exhibited significant buckling in knee extension suggesting that buckling is a component of healthy knee function. Like tendon crimp, buckling may serve as a protective mechanism, allowing the tissue to unwrinkle prior to undergoing pure strain. The links between increased buckling magnitude and both age and reduced activity suggest that excessive buckling may be maladaptive, though future work is necessary to elucidate this relationship. Buckling is relevant to consider when estimating tendon length, as buckling can lead to significant underestimation of resting length and thus overestimation of strain.

CONCLUSION

This study demonstrates the complexity of tendon behavior even in healthy adults undergoing passive motion, suggesting that buckling may be relevant to an improved understanding of tendon health and pathology.

Tears of popliteomeniscal fascicles, diagnostic and clinical implications. A review of the evidence

Postero-lateral corner of the knee is composed of several structures including the popliteo-meniscal fascicles (PMFs). These fibrous structures form a stable ligamentous complex around the popliteus tendon, which stabilize the lateral meniscus, increasing the strength of postero-lateral corner. Studies were retrieved through an electronic search of CINAHL, EMBASE, and Pub-Med, until May 2016. Studies in English, Italian, French, and Spanish were considered for inclusion. Randomized controlled trials, prospective and retrospective comparative studies, case series, and case reports were included. Studies eligible for inclusion concerned PMFs anatomy, biomechanics, diagnostic assessment of PMFs tears and clinical options for tears management. Thirteen studies were included in this review. There were: 7 case series, 4 case reports and 3 anatomical studies. Through anatomic dissection, two or three PMFs (antero-inferior fascicle, aiPMF; postero-superior fascicle, psPMF; postero-inferior fascicle, piPMF) can be indentified and isolated. Evaluation through MRI can be a useful diagnostic tool in detecting PMFs tears, especially using proton density (PD) sequences. The biomechanical analysis assessed that lateral meniscus (LM) motion is directly related with PMFs integrity and increased with section of one or both the fascicles. The clinical studies clearly state that a snapping syndrome, associated with lateral knee pain, can develop when one or both PMFs are torn. The three PMFs described are considered as relevant components of the popliteal hiatus, in the posterolateral aspect of the knee. MRI evaluation can detect these fibrous fascicles with good sensitivity. More studies with larger samples would be needed for a clear comprehension of PMFs function and clinical management of PMFs tears, especially with large case series and modern biomechanical testing.

Surgical Anatomy of the Knee A Review of Common Open Approaches

Knee-related complaints are among the most commonly encountered conditions by orthopaedic surgeons. Knee pathology varies widely and includes arthritis, deformities, fractures, infections, neuromuscular disorders, oncologic diseases, and soft-tissue injury. While nonoperative treatment modalities (activity modification, medications, injections, and physical therapy) are typically used as primary interventions, surgical treatment may ultimately become necessary. The purpose of this review is to discuss the most common open approaches to the knee, with an emphasis on surgically relevant anatomy for each approach. Understanding of the anatomy of the knee joint and associated neurovascular structures is necessary in order to avoid intraoperative complications and optimize postoperative recovery.

Investigating the relationship between internal tibial torsion and medial collateral ligament injury in patients undergoing knee arthroscopy due to tears in the posterior one third of the medial meniscus

PURPOSE

To evaluate the relationship between medial collateral ligament (MCL) injury and degree of internal tibial torsion in patients who had undergone arthroscopic resection due to tears in the posterior one third of the medial meniscus.

METHODS

Seventy-one patients were allocated into two groups with respect to foot femur angle (FFA) and transmalleolar angle (TMA) (Group 1 31 patients with FFA<8° and Group 2 40 patients with FFA≥8°). The groups were compared in terms of valgus instability, Lysholm score, magnetic resonance view, FFA, and TMA, both before and after the operation.

RESULTS

Lysholm scores were higher in Group 2 at both postoperative week 1 (p<0.001) and month 1 (p=0.045) relative to Group 1. Preoperative cartilage injury was encountered more frequently in Group 1 (p=0.037) than in Group 2. MCL injury was detected more frequently in Group 1 compared to Group 2 postoperatively at week 1 (p=0.001).

CONCLUSION

We conclude that FFA and TFA, indicators of internal tibial torsion, may serve as markers for foreseeing clinical improvement and complications following arthroscopic surgery.

LEVEL OF EVIDENCE

level III retrospective comparative study.

A Porcine Animal Model for Early Meniscal Degeneration - Analysis of Histology, Gene Expression and Magnetic Resonance Imaging Six Months after Resection of the Anterior Cruciate Ligament

BACKGROUND/OBJECTIVE

The menisci of the mammalian knee joint balance the incongruence between femoral condyle and tibial plateau and thus menisci absorb and distribute high loads. Degeneration processes of the menisci lead to pain syndromes in the knee joint. The origin of such degenerative processes on meniscal tissue is rarely understood and may be described best as an imbalance of anabolic and catabolic metabolism. A standardized animal model of meniscal degeneration is needed for further studies. The aim of the current study was to develop a porcine animal model with early meniscal degeneration.

MATERIAL AND METHODS

Resection of the anterior cruciate ligament (ACLR) was performed on the left knee joints of eight Göttingen minipigs. A sham operation was carried out on the right knee joint. The grade of degeneration was determined 26 weeks after the operation using histology and magnetic resonance imaging (MRI). Furthermore, the expression of 14 genes which code for extracellular matrix proteins, catabolic matrix metalloproteinases and inflammation mediators were analyzed.

RESULTS

Degenerative changes were detected by a histological analysis of the medial meniscus after ACLR. These changes were not detected by MRI. In terms of their gene expression profile, these degenerated medial menisci showed a significantly increased expression of COL1A1.

CONCLUSION

This paper describes a new animal model for early secondary meniscal degeneration in the Göttingen minipig. Histopathological evidence of the degenerative changes could be described. This early degenerative changes could not be seen by NMR imaging.

Arthroscopic Anterior Cruciate Ligament Reconstruction Using a Hamstring Graft with Interference Screw Fixation

Background and Aims:

This study assessed the clinical and radiographic results 3 to 8 years after an arthroscopic ACL reconstruction using a hamstring graft with interference screw fxation on femoral and tibial sites.

Material and Methods:

Seventy-six of 100 patients, who underwent an arthroscopic ACL reconstruction, could be re-examined with a mean follow-up of 5 years.

Results:

The mean Tegner activity score was 4 (scale: 0 to 10) before surgery, and 5 at the follow-up. Fifty-four patients (78%) achieved a satisfactory result in the IKDC rating. The mean Lysholm score was 85 (scale: 0 to 100), the score being better in patients without meniscal resection than those with (P = 0.04). The mean side-to-side difference in anterior-posterior knee laxity was 1.8 mm, and 62 patients (90%) had good stability. Sixty-four patients (93%) had normal range of motion of the knee. Twelve patients (46 %) with meniscal resection had osteoarthritic changes, compared with only 8 of those (20 %) without meniscal resection (P = 0.03).

Conclusions:

This medium-term follow-up study showed that good stability and function and normal range of motion of the knee can be achieved in majority of the patients who have undergone an ACL reconstruction with a hamstring graft and interference screw fixation.

Three-dimensional kinematic and kinetic gait deviations in individuals with chronic anterior cruciate ligament deficient knee: A systematic review and meta-analysis

BACKGROUND

Altered joint motion that occurs in people with an anterior cruciate ligament deficient knee is proposed to play a role in the initiation of knee osteoarthritis, however, the exact mechanism is poorly understood. Although several studies have investigated gait deviations in individuals with chronic anterior cruciate ligament deficient knee in the frontal and transverse planes, no systematic review has summarized the kinematic and kinetic deviations in these two planes.

METHODS

We searched five electronic databases from inception to 14th October 2013, with key words related to anterior cruciate ligament, biomechanics and gait, and limited to human studies only. Two independent reviewers assessed eligibility based on predetermined inclusion/exclusion criteria and methodological quality was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology statement checklist.

FINDINGS

We identified 16 studies, totaling 183 subjects with anterior cruciate ligament deficient knee and 211 healthy subjects. Due to the variability in reported outcomes, we could only perform meta-analysis for 13 sagittal plane outcomes. The only significant finding from our meta-analysis showed that individuals with anterior cruciate ligament deficient knee demonstrated a significantly greater external hip flexor angular impulse compared to control (P=0.03).

INTERPRETATION

No consensus about what constitutes a typical walking pattern in individuals with anterior cruciate ligament deficient knee can be made, nor can conclusions be derived to explain if gait deviations in the frontal and transverse plane contributed to the development of the knee osteoarthritis among this population.

[CLINICAL AND ARTHROSCOPIC FINDINGS IN MENISCAL INJURY AND KNEE INSTABILITY: A PROSPECTIVE STUDY]

INTRODUCTION

Medical history and physical examination are expected to provide the basic knowledge allowing diagnosis of a disease and thus enabling to plan the course of treatment.

OBJECTIVE

This study aimed to examine this hypothesis by comparing pre-operative diagnosis of meniscal and anterior cruciate ligament (ACL) injuries to final surgical findings.

MATERIAL AND METHODS

We prospectively compared the pre-surgical diagnosis to the arthroscopic findings in 753 arthroscopic procedures.

RESULTS

Clinical diagnosis of a medial meniscal (MM) tear was proven by arthroscopy in 65% of cases. Clinical diagnosis of a lateral meniscal (LM) tear was proven by arthroscopy in 54% of cases. Clinical complaints of instability correlated with partial or complete ACL rupture in 85% of cases. The accuracy of the clinical examination concerning ACL integrity ranged from 86% to 90%. Lachman and Pivot tests were slightly superior to the Drawer test.

DISCUSSION

Arthroscopic surgery is the most common surgical procedure in orthopedics. The diagnosis, which is based on history and physical examination in most cases, allows proper management of the case and an appropriate treatment plan. In most scenarios, these operations are conducted based on the diagnosis and treatment performed before surgery. In this study we showed that even in experienced and skilled hands, a clinical diagnosis of meniscal tear was approved by arthroscopy in only 54% to 65% of cases. A clinical diagnosis of ACL injury was approved by arthroscopy, in 99% of cases.

CONCLUSION

When planning conservative treatment or surgical intervention for a knee injury, it should be kept in mind that the clinical diagnosis of ACL rupture is highly reliable, while the clinical diagnosis of meniscal injury is only moderately reliable. Thus, especially when planning surgical intervention, the utilization of further imaging would be desirable when isolated meniscal injury is suspected.

[THE EVOLUTION IN TREATING MENISCAL TEARS--FROM RESECTION TO SUTURING]

The meniscus has an important biomechanical role in the normal function of the knee including load bearing, shock absorption and joint stability. Tears of the meniscus are one of the common sports injuries. The knowledge that total meniscectomy causes early development of degenerative changes has raised the prevalence of meniscal tear repair in order to preserve as much as possible of the meniscal tissue. The type of tear (degenerative of traumatic), shape and location have a critical effect on healing ability after suture of the tear and thus will determine the treatment plan.

[Case-control study on Chinese medicine fumigation and massage therapy for the treatment of knee stability and func tional recovery after anterior cruciate ligament reconstruction operation]

OBJECTIVE

To study clinical outcomes of Chinese medidine fumigation and massage therapy for the treatment of knee stability and functional recovery after anterior cruciate ligament reconstruction operation,and to explore the effect on tendon-bone healing.

METHODS

Total 50 patients were divided into two groups: the control group (normal rehabilitation therapy group),the treatment group (Chinese medicine fumigation and manipulation group). There were 25 patients in the control group, including 16 males and 9 females, who were treated with isometric muscle training, with the gradually enlarging amplitude of flexion and progressive loading of bearing training for knee recovery. There were 25 patients in the treatment group, including 15 males and 10 females,who were treated with the conventional rehabilitation therapy combined with Chinese medicine fumigation and massage therapy. The Chinese herbs named as Haitongpi decoction was steamed by a special equipment to fumigate the knee after operation; Based on the biomechanical parameters of the ligament reconstruction, the massage therapy was designed to control the degree of the knee flexion and release the adhesion for early recovery of knee functions. The Lysholm knee function evaluation system was used, and MRI examination was performed to measure the change in width of ligament tunnel in femur and tibia to evaluate the safety and stability of the treatment.

RESULTS

Lysholm system showed that two groups both had improving results from the 1st month after operation to the 3rd month (treatment group, F=36.54, P<0.05; the control group, F=28.12, P<0.05), and the results of the treatment group was better than that of the control group at the observation point (the 1st month, t=0.105, P<0.05; the 3rd month, t=5.361, P<0.01). There was no difference between the two groups when evaluating the bone and tendon healing 3 and 12 months after operation (P>0.05), indicating that Chinese rehabilitation therapy was a safety treatment without the influence on the loosing of tendon.

CONCLUSION

Chinese medicine fumigation and massage therapy can early improve the knee function after the anterior cruciate ligament reconstruction operation without the disturbance of the knee stability.

[Clinical effect of staged repair and reconstruction of multiple ligament injuries in knee joints]

OBJECTIVE

To evaluate clinical outcomes of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction under arthroscopy combined with limited open repair of medial collateral ligament (MCL) for the treatment of multiple ligament injuries of knee joints.

METHODS

From March 2006 and June 2012,the data of 14 patients (14 knees) with multiple injuries of ACL, PCL, and MCL were collected. There were 8 males and 6 females with an average age of (31.8 +/- 8.1) years old (ranged, 20 to 49 years old). All the patients were performed with X-ray and MRI examination, and the results showed that 10 patients had combined with injuries of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and medial collateral ligament (MCL); 4 patients had ALC,PCL and posterolateral corner (PLC) injuries. Four patients had medial meniscus injuries and 2 patients had lateral meniscus injuries. The MCL,PLC and meniscus injuries were treated with operation on the first stage, and functional exercises were performed 3 weeks after fixation. The reconstruction operation of ACL and (or) PCL was performed at the second stage under arthroscopy 3 to 6 months later when the movement range of knee joint recovered to the normal level with obvious relaxation.

RESULTS

All incisions healed by primary intention. All the patients were followed up with a mean duration of 48.9 months (ranged, 24 to 80 months). The Lysholm score was improved from preoperative 19.6 +/- 0.9 to the latest follow-up 87.1 +/- 2.8 (t=12.3, P<0.01). The International Knee Documentation Committee (IKDC) rating: 9 cases nearly recovered to normal, 5 cases were abnormal.

CONCLUSION

For multiple ligament injuries in the knee, staged repair and reconstruction can effectively restore knee joint stability and function.

Influence of lateral meniscal posterior root avulsions and the meniscofemoral ligaments on tibiofemoral contact mechanics

PURPOSE

The purpose of this study was to investigate the effect of lateral meniscal posterior root avulsions combined with intact meniscofemoral ligaments (MFLs), deficient MFLs, anterior cruciate ligament (ACL) tears and reconstructions, and root repairs using an established tibiofemoral contact mechanics testing protocol.

METHODS

Ten fresh-frozen cadaveric knees were tested with six knee conditions (1: intact; 2: lateral meniscal posterior root avulsion; 3: root avulsion and deficient MFLs; 4: condition 3 with ACL tear; 5: condition 4 with ACL reconstruction; 6: ACL reconstruction with root repair) at five flexion angles (0°, 30°, 45°, 60°, and 90°), under a 1000-N axial load. Contact area and pressure were measured with Tekscan sensors.

RESULTS

Compared to the intact state, condition 2 did not significantly change lateral compartment contact area or pressure. Changes in contact mechanics were greater at increased flexion angles; for condition 3 at 0° and 90°, contact area decreased 37 and 52 % [95 % CI (21-53) and (39-66), respectively] and mean contact pressure increased 55 and 87 % [95 % CI (33-76) and (59-114), respectively]. Root repair with ACL reconstruction was not significantly different from the intact state.

CONCLUSIONS

The MFLs protect the lateral compartment from changes in contact mechanics in the setting of a lateral meniscal posterior root avulsion, whereas a combination of lateral meniscal root avulsion and deficient MFLs leads to significant changes. Concurrent ACL reconstruction and lateral meniscal root repair restore mean contact pressure and area to the intact state and are recommended in this combined injury to prevent or slow the development of lateral compartment arthritis.