Patellar tendinopathy with intratendinous alteration on MRI may be related to patellofemoral dysplasia.

Patellar tendinopathy (PT) is a frequent overuse injury of the extensor knee apparatus, whereas as up to 30% of the athletes might suffer from persisting symptoms during their entire career. In the present case-control study, 47 patients (30.8 ± 11.4 years) with PT with intratendinous alteration (PTita) of a minimum of ≥25% of the axial surface on MRI and minimum Blazina score of II (pain during without limiting sports activity) were included; MR images were analyzed for trochlear geometry, patellar height/tilt, and tibial tubercle-trochlear groove distance (TT-TG). The control group (CG) comprised 87 age- and gender-matched patients without history of anterior knee pain or lateral patellar instability. It was hypothesized that patients with PT might be related to patellofemoral dysplasia. It was found that the patella was significantly higher in patients with PT compared to the CG (patellotrochlear index [PT-I]: 0.33 vs 0.37, P = .014; Insall-Salvati index [InSa]: 1.18 vs 1.07, P = .004). PT-I was above the cut-off value in 10.6% of PT knees (CG 5.7%, P = .27), and InSa in 42.6% (CG 21.8%, P = .012). TT-TG was significantly higher in patients with PT compared to CG (12.0 mm vs 9.9 mm, P = .002); however, TT-TG was only pathologic (>20 mm) in one patient. The trochlear facet ratio was above the cut-off value in 55.3% of PT patients and 23% of CG (P < .001), and was significantly greater in patients with PT (0.39 ± 0.09) than CG (0.48 ± 0.1, P < .001). Knees with PT have significantly more morphological characteristics of patellofemoral instability, which needs to be considered especially in recurrent or treatment-refractive cases.

Landmarks of the normal adult human trochlea based on axial MRI measurements: a cross-sectional study.

PURPOSE: For deepening trochleoplasty, a procedure used worldwide to correct trochlear dysplasia, only few surgical steps are described precisely. Important surgical landmarks, such as optimal cartilaginous trochlear depth and percentages of the new lateral and medial facet, remain unanswered. METHODS: A cross-sectional study (January 2011-August 2012) was carried out in adult patients (16-35 years) without trochlear dysplasia, who underwent magnetic resonance imaging (MRI). The main outcome was trochlear depth. The secondary outcome was the lateral/medial facet ratio. Measurements were made on the first axial cut from proximal with complete cartilage coverage of the trochlea. Differences between men and women were assessed. RESULTS: Fifty-three patients (70% men) were included. Mean age was 24.6 years (SD±5.5). Overall mean trochlear depth was found to be as 4.0 mm (95% CI 3.6-4.3). Values differed significantly by gender (p=0.0271) with a mean of 3.4 mm (95% CI 3.0-3.8) for women and a mean of 4.2 mm (95% CI 3.8-4.7) for men. The mean ratio between the lateral and medial facet was 1.71 (95% CI 1.62-1.80), the lateral facet contributing 62.6% (95% CI 61.3-63.8) and the medial facet contributing 37.4% (95% CI 36.2-38.7) to the total cartilage length. For the facet ratio, there was no statistically significant gender difference (n.s.). CONCLUSIONS: This study provides data on important landmarks for deepening trochleoplasty based on average MRI measurements in the general population. The difference between the MRI measurement and actual cartilage surface measurement is likely to be minimal, but is yet to be evaluated. Further evaluation of these landmarks by prospectively performing deepening trochleoplasty will determine the value of the clinical implication. LEVEL OF EVIDENCE: II.

3D representation of the surface topography of normal and dysplastic trochlea using MRI.

The three-dimensional (3D) image of the articular surface topography of the normal and the dysplastic trochlea has not been defined. The aim of this study was to represent both the normal and dysplastic trochlear geometry in 3D using magnetic resonance imaging (MRI). Using the segmentation software program Amira (Mercury Computer Systems, Inc., Chelmsford, USA) we created 3D reconstructions of the distal femur bone and cartilage using MRI scans. Bone and cartilage of the distal femur were traced slice by slice in the acquisitioned dimension while the Amira program reconstructed the 3D model. This model was then transferred to the Rhinoceros 4.0 software (Robert McNeel & Associates, Seattle, USA) for measuring. Using this system a non-invasive 3D representation of the articular cartilage and bone of the normal trochlea and depiction of different types of trochlear dysplasia were possible. Potential advantages of these MRI measurements are assessment of the 3D articular cartilage of the whole trochlea and the bony contours on the same image, no imaging errors from joint malpositioning, no ionizing radiation, precise preoperative planning according to the documented pathomorphology, and comparison between the preoperative and the postoperative shapes. The disadvantages include higher costs compared to radiography or CT scans, and time consuming reconstruction, making them currently a research tool.

[Isolated arthrosis of the patellofemoral joint in younger patients (<50 years)]. / Isolierte Arthrose des Patellofemoralgelenks beim jüngeren Patienten (<50 Jahre).

In the majority of cases, arthrosis of the patellofemoral joint (PFJ) is combined with arthrosis of the femorotibial compartment and thus assumes a somewhat secondary role. Nevertheless, it can occur as an isolated entity. Several radiological studies evidenced isolated degenerative alterations in the PFJ in the age group >55 years (13.6-24.0% in women and 11.0-15.4% in men). In younger patients the incidence is lower and is mainly associated with patellar instability or post-traumatic arthrosis. Just the same, the choice of appropriate treatment for these patients is challenging. Total replacement can be recommended for older and less active patients. In contrast, for younger and more active patients, various conservative treatment options and more demanding operative techniques are available to the surgeon to avoid arthroplasty. This article describes the different therapeutic possibilities for managing arthrosis of the PFJ in patients aged <50 years.

[Osteotomies]. / Osteotomien.

Skeletal geometry, soft tissues, and neuromuscular control influence the patellofemoral gliding mechanism. Abnormal skeletal geometry - such as increased femoral anteversion, trochlear dysplasia, patella alta, increased tibial external torsion, increased tibial tubercle lateralization, and variations of combined deformities - may lead to patellofemoral complaints. Altered vectors and forces acting on the patellofemoral joint can cause cartilage failure with later arthrosis, instability, and musculotendinous insufficiency. Osteotomy with soft tissue repair might be the best treatment, depending on the primary pathology. Surgery aims to eliminate the underlying pathomorphology.

[Biomechanical issues in patellofemoral joint rehabilitation]. / Biomechanische Aspekte in der Rehabilitation des Patellofemoralgelenks.

Specific knowledge of the biomechanics of the patellofemoral joint is crucial for successful nonoperative or postsurgical rehabilitation. The biomechanical aspects of different situations should be considered when designing an exercise program. Joint reaction forces, contact area, and contact stress are dependent on flexion angle and exercise situations. In weight-bearing activities, the amount of knee flexion directly influences the magnitude of quadriceps muscle force, which affects the magnitude of patellofemoral joint reaction forces. Open and closed chain exercises should be performed within a safe range of motion to allow quadriceps activation while minimizing patellofemoral joint reaction forces. The isolated knee extension (90 degrees -40 degrees ), the squat (0 degrees -30 degrees -60 degrees ), and the leg press (0 degrees -30 degrees -60 degrees ) are the three main exercise situations in the acute rehabilitation phase. Controlled body positions and low levels of pain and symptoms should also be emphasized to achieve a functional progression, focusing on neuromuscular control.

[Women's soccer. Injuries, risks, and prevention]. / Frauenfussball. Verletzungen, Risiken und Prävention.

Women's soccer participation is becoming a trend in sport. With increasing number of licensed female soccer players, there is also an increase in sport specific injuries. This fact has socioeconomic importance. The larger pelvic bone leading to an increased internal rotation of the femur, the narrower intercondylar notch as well as the unfavorable strength ratio of the hamstrings vs. the quadriceps muscle lead to an increased risk for injuries of the anterior cruciate ligament in female soccer.Several studies showed that intervention programs based on neuromuscular or proprioceptive training or intensive strengthening of the hamstrings can reduce the incidence of injuries. Moreover, the importance of sufficient rehabilitation after injuries has to be emphasized, as the reoccurrence of injury is high.

Correlation between the Q angle and the patella position: a clinical and axial computed tomography evaluation.

The purpose of this study was to evaluate the significance of the Q angle with respect to the patella position. Fifty-six knee joints of 34 patients (15 bilateral) with chronic patellofemoral pain were prospectively evaluated. All patients were examined by the same orthopaedic surgeon (R.M.B.) and the Q angle measured clinically and using long radiographs. Additionally, axial computed tomography (CT) scans were obtained through the center of the patellar articular cartilage in 0 degrees of flexion. Three different patellofemoral indices were measured by the second author (K.W.), who was not involved in the clinical examination: lateral patellar displacement (LPD), lateral patellar tilt (LPT), and patella-lateral condyle index (PLCI). These results were compared with the values of the measured Q angle. For statistical analysis, the Pearson correlation coefficient was calculated and the Statistical Package for Social Science (SPSS) used. A pvalue < 0.05 was considered significant. We could not find a significant correlation between the Q angle values and the patellofemoral indices in all patients (bilateral or only right/left). Within the patients with bilateral patellofemoral pain (n = 15), there was a significant correlation between LPD and PLCI (p = 0.015), LPT and PLCI (p = 0.024) left and LPD and LPT(p = 0.011) right. Similar results were found in patients with pain only on one side. In conclusion, there is no significance between the Q angle and the position of patella. The diagnostic relevance of the Q angle could not be established.

Free nerve endings in the medial and posteromedial capsuloligamentous complexes: occurrence and distribution.

Free nerve endings (FNEs) of type IVa play a distinctive role in the articular nociceptive and sensorimotor system of the knee. This study qualitatively and quantitatively analyzed FNEs in the medial and posteromedial capsuloligamentous complexes. Biopsy specimens from ten precisely defined anatomical locations were taken from seven fresh cadaver knee joints. The specimens were fixed with 4% formaldehyde solution and stained with hematoxylin-eosin. The results were examined using immunohistochemistry. The occurrence of FNEs is described in combination with their specific pattern of distribution. A high number of FNEs were found in all investigated elements with a maximum relative density in the insertion of the semimembranosus muscle in the direct attachment on the tibial margin. The number was lowest in the superficial medial collateral ligament. The results were correlated with anatomical and biomechanical functions of the stabilizing effect of the medial capsuloligamentous complex. Our findings indicate that lesions and surgical procedures can alter normal sensory feedback and coordination by modifying the use of muscle fiber during specific movements.

Treatment of intrasubstance meniscal lesions: a randomized prospective study of four different methods.

This study examined the effect of four different methods for treating intrasubstance meniscal lesions. Forty patients (21 men, 19 women; age 30.4 years, range 16-50) with an isolated and symptomatic painful horizontal grade 2 meniscal lesion on the medial side (documented with MRI) were included. Patients were randomly assigned by the birth date to one of four treatment groups: group A, conservative therapy (n = 12); group B, arthroscopic suture repair with access channels (n = 10); group C, arthroscopic minimal central resection, intrameniscal fibrin clot and suture repair (n = 7); and group D, arthroscopic partial meniscectomy (n = 11). The average length of follow-up was 26.5 months (range 12-38 months). Follow-up evaluation consisted of clinical examination with the findings recorded according to the IKDC protocol, radiographs, and control MRI. Group A had 75% normal or nearly normal final evaluation at follow-up, group B 90%, group C 43%, and group D 100% normal or nearly normal at follow-up. These short-term results indicate that intrasubstance meniscal lesions can be treated best by performing partial meniscectomy. To preserve the important function of the meniscus, arthroscopic suture repair with access channels might give even better medium- to long-term results. Conservative treatment is often not satisfactory. Additionally, our findings show that MRI examinations are not superior to accurate clinical examinations.

Ligament-muscle reflex arc after anterior cruciate ligament reconstruction: electromyographic evaluation.

The purpose of this study was to determine if a ligament-muscle reflex arc exists between the bone-patellar tendon-bone autograft after anterior cruciate ligament (ACL) reconstruction and the hamstring muscle group. We studied four patients, average age 34.2 years (range 32-36 years). The mean time between the ACL reconstruction and the study examination was 56.2 months (range 5-108 months). All patients underwent a second-look arthroscopy for meniscal injuries, cyclops lesions, or adhesions. Five patients with a normal ACL served as a control group before we performed an arthroscopic meniscectomy. Electromyographic (EMG) activity was measured using fine wire electrodes under two different testing conditions. No unequivocal EMG activity could be detected in the ACL-reconstructed knees when we pulled on the graft or in the controls. Three of four patients and all controls felt pain when we touched the graft or normal ACL or applied strain on it with the hook. In conclusion, the ACL autograft presents a noxious sensory innervation, the Lachman test maneuver stimulates a reflex arc with hamstrings activation, and an unequivocal ligament-muscle reflex arc from the graft to the hamstring muscle group could not be demonstrated.

[Overuse syndrome of the soft tissues of the lower extremity]. / Uberlastungssyndrome der Weichteile der unteren Extremität.

Sports activities with high demands and stresses to the musculoskeletal system increase the risk of overuse injures. The etiologic mechanisms are multifactorial, with both intrinsic and extrinsic factors. In spite of better diagnostic equipment and conservative methods of treatment, some of these overuse injuries do not heal and a structural damage of the tissue remains. Thus, surgery is often the only way to relieve the symptoms and to restore normal function. This article provides a basic overview of the epidemiology, anatomy, biomechanical factors, stress responses and therapeutic principles regarding overuse injuries of the soft tissues.

Intracompartmental pressure before and after fasciotomy in runners with chronic deep posterior compartment syndrome.

Exercise induced pain in the posterior part of the leg is common among runners; the underlying reason for these complaints may be very different. The purpose of the present, controlled study was therefore 1. to confirm a clinically diagnosed deep posterior compartment syndrome by using intramuscular pressure measurements and 2. to evaluate the effect of a surgical release on clinical signs and intracompartment pressure values. Fifteen symptomatic runners with the clinical suspicion of a chronic deep posterior compartment syndrome and nine healthy recreational runners as controls were investigated. Intramuscular pressure was measured both at rest and up to two minutes post-exercise, using a pressure-monitor with a transducer. In symptomatic runners, the average pressure was preoperatively 5.6 mmHg (95%-confidence-interval [CI]: 3.4-7.6) at rest, rising to 18.5 mmHg (CI: 15.4-21.8) post-exercise. Corresponding values in healthy control runners were 5.1 mmHg (CI: 1.9-8.3) at rest, with a decrease induced by exercise to 2.8 mmHg (CI: -0.5-6.1). After fasciotomy of the deep posterior compartment in all fifteen symptomatic runners, average pressure values fell to 2.2 mmHg (CI: 1.0-3.4) at rest, and were further reduced after (now pain-free) exercise to 1.6 mmHg (CI: 0.6-2.6). The decrease between pre-operative and post-operative values was statistically highly significant (p < 0.0001 for values after running, p < 0.005 for values at rest). In conclusion, intracompartment pressure measurement is a useful technique to confirm the clinical diagnosis of deep posterior compartment syndrome prior to recommending surgery. Hereby, an exercise-induced rise in pressure of at least 10 mmHg, corresponding to a two- to threefold increase of values measured at rest, may be a more important diagnostic criterion than absolute levels of pressure measured before or after running.

Quantitative gait analysis in patients with medial patellar instability following lateral retinacular release.

Medial patellar instability is a known possible complication following lateral retinacular release. Insufficient passive structures, muscle imbalance and an over-release of the lateral retinaculum with resection of the vastus lateralis tendon have been implied as a major cause of this problem. We report about the findings of quantitative gait analysis consisting of video recordings, three-dimensional motion analysis, dynamic electromyography and sampling of the ground reaction forces in two patients with medial patellar subluxation. Documentation of the gait functions together with observation of the patellar translation revealed the timing of the occurrence of the instability during level gait: a normal gait pattern with a sufficient quadriceps mechanism and a centred patella was seen during loading (weight acceptance), while the quadriceps muscle was active. Abnormal medial translation of the patella was observed during unloading of the leg while the knee was bending in preparation for the swing phase. This is a phase in the gait cycle when the quadriceps muscle is silent and the patella position is guided by the passive structures only. This finding weakens the argument of muscle imbalance as a cause for the patellar instability and stresses the importance of well balanced passive structures. This explains why a muscular rehabilitation programme is likely to fail as long as the passive structures allow the instability to occur.

Axial computed tomography of the patellofemoral joint with and without quadriceps contraction.

Computed tomography was used to analyze the patellofemoral relationship during the first 60 degrees of knee flexion in patients with chronic patellofemoral pain syndrome (49 knees) and a healthy control group (15 knees). The patellofemoral joints were imaged axially through the center of the patella articular cartilage with the knee flexed 0 degrees, 0 degrees with maximal quadriceps muscle contraction, 30 degrees, and 60 degrees. In 0 degrees of knee flexion, the sulcus angle was greater in the symptomatic group than in normal controls. The patella displaced further laterally, and the lateral patellar tilt was greater. The patellar lateral index was found to be greater at 0 degrees and indicated severe abnormality with full quadriceps muscle contraction. The Laurin angle was pathologic with increased medial opening, especially with muscle contraction. At 30 degrees of knee flexion, these differences were less marked than at 0 degrees. No relevant differences were found with 60 degrees of knee flexion. This study showed that the sulcus angle, lateral patellar displacement, lateral patellar tilt, patella lateral condyle index, and Laurin angle are relevant diagnostic features in 0 degrees of knee flexion, indicating a pathological femoral patellar gliding mechanism. Our evaluation also demonstrated the influence of full quadriceps muscle contraction, especially regarding lateral patellar displacement and the Laurin angle, and it was most prominent on the patella lateral condyle index. Thus, quadriceps muscle contraction often creates a more pathological displacement of the patella, which can be depicted using axial computed tomography.

[To stay fit inspite of injury]. / Trotz Verletzung leistungsfähig bleiben.

Optimal rehabilitation after injuries has become increasingly important in recent years. In our concept, not only the damaged local structure is treated but supplementary training to improve the general physical performance is recommended. This specific training includes the components of strength, endurance, coordination, flexibility and velocity. We explain in the present article the role of these rehabilitative methods and refer to their importance for the reintegration process following injuries.

Atrophy of the infraspinatus muscle caused by a suprascapular ganglion.

CASE SUMMARY: Herein is reported a case of a 21-year-old ice hockey player with a suprascapular ganglion causing atrophy of the infraspinatus muscle. DISCUSSION: Lesions of the suprascapular nerve can be caused by trauma of compression. While the suprascapular nerve entrapment syndrome results in atrophy of both the supraspinatus and the infraspinatus muscles, compression of the nerve distal to the spinoglenoid notch leads to isolated weakness of the infraspinatus muscle.

[Femoropatellar pain syndrome: which operation is still sensible?]. / Femoropatelläres Schmerzsyndrom: Wann ist welche Operation uberhaupt noch sinnvoll?

The generalized use of some few operative treatments (medialization and advancement of the tuberosity of the tibia, abrasion and forage, lateral retinacular release) for most of patellofemoral pain syndromes without regard to the pathology might cause severe secondary problems. Therefore, a more conservative approach is often preferred. Nevertheless, there exist specific indications for surgical interventions after accurate evaluation of the etiological pathology. Some typical examples are described in three groups [mechanical disorders, malalignment, dysplasias], considering the causing factors.