Vicente Sanchis-Alfonso

Immunohistochemical Analysis for Neural Markers of the Lateral Retinaculum in Patients with Isolated Symptomatic Patellofemoral Malalignment A Neuroanatomic Basis for Anterior Knee Pain in the Active Young Patient

We evaluated 13 lateral retinacula excised at the time of Insall proximal realignments or isolated lateral retinacular releases performed in patients with isolated symptomatic patellofemoral malalignment recalcitrant to nonoperative treatment. Evaluation was performed by means of conventional histologic and immunohistochemical analysis for neural markers (S-100 protein, neurofilament protein, substance P, and neural growth factor). The observations reported here provide a neuroanatomic basis for anterior knee pain syndrome in active young patients with isolated symptomatic patellofemoral malalignment and support the clinical observation that the lateral retinaculum may have a key role in the origin of this pain as a result of increased neural growth factor production, which induces proliferation of nociceptive axons, mainly in a perivascular location.

Quantitative analysis of nerve changes in the lateral retinaculum in patients with isolated symptomatic patellofemoral malalignment : A preliminary study

Neural damage in 16 lateral retinacula excised at the time of Insall proximal realignments or isolated lateral retinacular releases performed in patients with symptomatic patellofemoral malalignment was evaluated by means of conventional histology and immunohistochemical and morphometric analyses. A relationship between clinical and histologic findings was found. An increase in the proportion of innervated tissue was correlated with anterior knee pain syndrome. We found a significant relationship between total neural area and pain. The group with moderate pain had the highest number of nerves and the highest neural area. In reference to total neural area and pain, there was a significant difference only between the patients with moderate pain and those with light pain, but not between patients with severe pain and those with moderate pain. The group with severe pain also showed a high neural area, although with a lower number of nerves. The severe-pain group had the largest nerves (24% of nerve fibers surpassing 25 m diameter) in a zonal disposition, in which there were groups of nerve fibers in some fields and no nerve fibers in others. The group with moderate pain had an increase in medium and small nerve fibers (mean diameter, 18 m), predominantly of tiny perivascular fibers. Moreover, we believe that instability in patients with patellofemoral malalignment can be explained in part because of loss of proprioception due to neural damage.

Healing of the patellar tendon donor defect created after central-third patellar tendon autograft harvest A long-term histological evaluation in the lamb model

Abstract Patellar tendon donor defect (PTDD) healing after patellar tendon autograft (PTA), was evaluated in 12 lambs (24 knees), by means of conventional histology, immunohistochemistry and image analysis. The results of this study indicate that the PTDD is replaced by a tissue that does not assume the histological characteristics of a normal patellar tendon. Both the Hoffa fat pad (HFP) and the paratenon play an important role in the healing process, although qualitative and quantitative chronological differences were found, which supports the concept of a “two-time process”. The HFP initiates the repair process, and is the main active proliferative tissue compartment during the first week. Once the process is established, the paratenon and, in particular, its synovial lining, starts proliferative activity and virtually substitutes that of the HFP, which rapidly loses activity in a few days. Moreover, donor-site morbidity after PTA could be the result of histological changes in the patellar tendon and environs in only a few cases. We have found inflammatory and neural changes in the refilled PTDD that could explain the anterior knee pain after PTA. Likewise, we have observed loss of Golgi corpuscles in the refilled PTDD, which could lead to proprioceptive loss after ACL reconstruction with PTA. Finally, we have observed shrinkage of the PTDD scar that could contribute to the etiopathogenia of a patella infera.

Neural growth factor expression in the lateral retinaculum in painful patellofemoral malalignment

We studied 7 samples of lateral retinaculae excised at the time of surgical realignments. They were obtained from patients with isolated symptomatic patellofemoral malalignment resistant to conservative treatment and were evaluated with immunohistochemistry and immunoblotting. We found that neural growth factor is higher in patients with pain than in those with instability as the main symptom. Neural growth factor is related to neural proliferation in vessels and perivascular tissue and to the release of neuroceptive transmitters, such as substance P. We postulate that both mechanisms are involved in the pathogenesis of pain in isolated symptomatic patellofemoral malalignment.

Histologic retinacular changes associated with ischemia in painful patellofemoral malalignment

Ischemic changes in 31 samples of lateral retinacula excised at surgical realignment in patients with isolated symptomatic patellofemoral malalignment resistant to conservative treatment were evaluated with conventional histology, electron microscopy, immunohistochemistry, and molecular biology. Morphologic and ultrastructural changes associated with ischemia including hypervascularization and increased vascular endothelial growth factor release were identified in painful patellofemoral malalignment. It is hypothesized that periodic short episodes of ischemia could be implicated in the pathogenesis of anterior knee pain in most cases of isolated symptomatic patellofemoral malalignment in active young patients by triggering neural proliferation.

Intra-articular osteoid osteoma of the humerus with synovitis simulating chronic monoarthritis of the elbow in a recreational tennis player

We present a case of intra-articular osteoid osteoma of the humerus simulating chronic monoarthritis of the elbow in an 18-year-old male right-handed recreational tennis player. CT revealed a well-defined nidus in the coronoid fossa. Microscopic examination of the synovium showed a lymphofollicular synovitis that resembled the synovitis in rheumatoid arthritis.

Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies

Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical indication or inappropriate surgical technique/patient selection; (2) a technical error; and (3) an incorrect assessment of the concomitant risk factors for instability. An understanding of the anatomy and biomechanics of the MPFL and cautiousness with the imaging techniques while favoring clinical over radiological findings and the use of common sense to determine the adequate surgical technique for each particular case, are critical to minimizing MPFL surgery failure. Additionally, our approach to dealing with failure after primary MPFL reconstruction is also presented.

Medial Patellar Instability: A Little Known Cause of Anterior Knee Pain

Anterior knee pain (AKP) is one of the most common patient complaints heard by orthopedic surgeons. A wide variety of causes of AKP have been ascribed to it. Medial patellar instability (MPI) is an objective condition with its own personality provoking incapacitating AKP that should be included in the differential diagnosis of AKP patients, above all in disabling AKP patients after realignment surgery. However, this condition can be difficult to diagnose because it is not well described in the medical literature. Its clinical repercussion was identified at the end of the 1980s. We can now state that it is an objective cause of AKP and that it is more frequent than we had thought, although it might be underdiagnosed because it is still not a well-known entity. The first author has seen many patients with MPI who have seen more than three physicians without a true diagnosis of their condition.

Laboratory evaluation of the pivot-shift phenomenon with use of kinetic analysis: a preliminary study.

BACKGROUND Currently, a suitable and reliable noninvasive method to evaluate rotational stability in vivo in anterior cruciate ligament-deficient knees, particularly during sports movements, does not exist. We speculated that if there is a rotational instability, the patient would avoid reaching a high pivoting moment during pivoting activities as a defense mechanism, and that the ground reaction moment, as registered by dynamometric platforms, would be reduced. On the basis of this hypothesis, we developed a study using kinetic analysis to evaluate rotational stability under dynamic loading. METHODS Thirty recreationally active athletes, including fifteen healthy subjects and fifteen with an anterior cruciate ligament-deficient knee, were recruited for this study. Patients performed jumping with pivoting with internal tibial rotation and external tibial rotation on the dynamometric platform with both the healthy and the injured limb. The quantitative results were graphically plotted, and the following parameters were evaluated: loading moment, pivoting moment, torque amplitude, loading slope, pivoting slope, percentage of pivoting with load, loading impulse, pivoting impulse, and maximum body rotation angle. RESULTS There were no significant differences between the dominant and nondominant knees in the control group during the jumping with pivoting and external tibial rotation test with regard to the pivoting moment (p = 0.805), pivoting slope (p = 0.716), pivoting impulse 2 (p = 0.858), and pivoting impulse 3 (p = 0.873). In patients with a chronic tear of the anterior cruciate ligament, there was a significant decrease of the pivoting moment (p = 0.02), pivoting slope (p = 0.005), pivoting impulse 2 (p = 0.006), and pivoting impulse 3 (p = 0.035) during the jumping with pivoting and external tibial rotation test in the anterior cruciate ligament-deficient knee compared with the healthy, contralateral knee. CONCLUSION Kinetic analysis with use of a dynamic platform can objectively detect alterations of rotational stability in anterior cruciate ligament-deficient knees, which may allow this to be a useful research tool for evaluating treatment strategies in patients with anterior cruciate ligament injuries.

Pathogenesis of Anterior Knee Pain and Patellar Instability in the Active Young

This study is not intended to advocate for a particular surgical technique, but it does provide insight into improving our understanding of the pathophysiology of anterior knee pain syndrome. Our objectives were: to identify a relationship, or lack of one, between the presence of PFM and the presence of anterior knee pain and/or patellar instability; to analyze the long-term response of VMO muscle fibers to increased resting length; and to determine the incidence of patellofemoral arthrosis after IPR surgery. Our findings indicate (1) that not all PFM knees show symptoms; that is, PFM is not a sufficient condition for the onset of symptoms, at least in postoperative patients; (2) that the advancement of VMO has no deleterious effects on VMO; and (3) that IPR does not predispose to retropatellar arthrosis.