Medial patellofemoral muscle: report of a rare variant / Músculo patelofemoral medial: reporte de una rara variante

Muscle anatomic variants range from absence of a muscle to supernumerary muscles, with a spectrum of possibilities that include anomalous course, anomalous origin or insertion, accessory slips, and others. The most common muscle variants around the knee include aberrant origin and accessory slips of the gastrocnemius muscles, presence of tensor fascia suralis muscle, and accessory popliteus. The medial patellofemoral ligament is a distinct extra-articular condensation of fibers located superficially to the medial joint capsule. We describe the presence of an accessory medial patellofemoral muscle in the expected location of the medial patellofemoral ligament, which to our knowledge has not been described in the literature before.

Las variantes anatómicas musculares van desde la ausencia de un músculo hasta la presencia de músculos supernumerarios, en un espectro de posibilidades que incluyen trayecto anómalo, origen anómalo o inserción, fascículos accesorios, y otros. Las variantes más comunes de músculos presentes alrededor de la rodilla incluyen el origen aberrante y fascículos accesorios del músculo gastrocnemio, la presencia del músculo tensor de la fascia sural y el músculo poplíteo accesorio. El ligamento medial patelofemoral es una clara condensación extra-articular de fibras localizado superficialmente a la cápsula articular medial. Se describe la presencia de un músculo patelofemoral medial accesorio en la ubicación esperada del ligamento patelofemoral medial, que a nuestro conocimiento no se ha descrito antes en la literatura.

[The Linburg-Comstock phenomenon: a review]. / Die Linburg-Comstock-Variante: Eine Übersicht.

Simultaneous flexion of thumb and fingers is described as the Linburg-Comstock phenomenon. Congenital and acquired coupling of the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) tendons is the reason for this clinical entity. Additionally, coupling of the FPL and the flexor digitorum superficialis II or III has been described. The coupling can be between the muscles, the tendon sheaths or the tendons themselves. Asymptomatic and symptomatic coupling should be differentiated. In general symptomatic congenital or acquired coupling demands surgical intervention. We report about a 35-year-old patient with a congenital asymptomatic coupling of FPL and FDP-II who suffered a distorsion of the thumb. Afterwards she complained of pain and strength loss. An accessory tendon of 3 mm in diameter and 3.5 cm length between FPL and FDP-II was identified during surgery. The patient recovered completely after resection of this coupling.

Patellar tendon tenodesis in association with tibial tubercle distalization for the treatment of episodic patellar dislocation with patella alta.

BACKGROUND: The association between patella alta and episodic patellar dislocation (EPD) has been well described, but its pathophysiology is not completely clear. Patella alta causes decreased contact between the patella and trochlea and decreased resistance to lateral translation of the patella. Additionally, increased patellar tendon length may allow pathologically increased coronal plane patellar motion. It may thus be desirable to address the length of the patellar tendon itself rather than just its insertion site. HYPOTHESIS: Tenodesis of the patellar tendon in association with tibial tubercle distalization in patients with EPD and abnormally long patellar tendons (>52 mm) results in significant reduction in patellar tendon length, prevention of further patellar dislocation, and good knee function at long-term follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-seven knees in 22 patients with EPD and patella alta were treated with patellar tendon tenodesis and tibial tubercle distalization. Following tubercle distalization, the patellar tendon was tenodesed into the original location of the tibial tubercle with suture anchors. Changes in patellar tendon length and patellar height were measured radiographically. Any recurrent dislocation was documented, and patients completed an International Knee Documentation Committee (IKDC) subjective form at a mean of 9.6 years (range, 6-14 years) after surgery. RESULTS: The mean length of the patellar tendon decreased from 56.3 ± 2.7 mm to 44.3 ± 8.6 mm (P < .0001). The Caton-Deschamps index decreased from 1.22 ± 0.17 to 0.95 ± 0.22 (P < .0001), and the Insall-Salvati ratio decreased from 1.42 ± 0.17 to 0.91 ± 0.18 (P < .0001). No patellar dislocations occurred postoperatively. The mean postoperative subjective IKDC score was 75.6 ± 9.5. CONCLUSION: Patellar tendon tenodesis and tibial tubercle distalization result in normalization of patellar tendon length, a stable patellofemoral joint, and good long-term knee function in patients with patella alta and EPD.

Effect of implanting a soft tissue autograft in a central-third patellar tendon defect: biomechanical and histological comparisons.

Previous studies by our laboratory have demonstrated that implanting a stiffer tissue engineered construct at surgery is positively correlated with repair tissue stiffness at 12 weeks. The objective of this study was to test this correlation by implanting a construct that matches normal tissue biomechanical properties. To do this, we utilized a soft tissue patellar tendon autograft to repair a central-third patellar tendon defect. Patellar tendon autograft repairs were contrasted against an unfilled defect repaired by natural healing (NH). We hypothesized that after 12 weeks, patellar tendon autograft repairs would have biomechanical properties superior to NH. Bilateral defects were established in the central-third patellar tendon of skeletally mature (one year old), female New Zealand White rabbits (n = 10). In one limb, the excised tissue, the patellar tendon autograft, was sutured into the defect site. In the contralateral limb, the defect was left empty (natural healing). After 12 weeks of recovery, the animals were euthanized and their limbs were dedicated to biomechanical (n = 7) or histological (n = 3) evaluations. Only stiffness was improved by treatment with patellar tendon autograft relative to natural healing (p = 0.009). Additionally, neither the patellar tendon autograft nor natural healing repairs regenerated a normal zonal insertion site between the tendon and bone. Immunohistochemical staining for collagen type II demonstrated that fibrocartilage-like tissue was regenerated at the tendon-bone interface for both repairs. However, the tissue was disorganized. Insufficient tissue integration at the tendon-to-bone junction led to repair tissue failure at the insertion site during testing. It is important to re-establish the tendon-to-bone insertion site because it provides joint stability and enables force transmission from muscle to tendon and subsequent loading of the tendon. Without loading, tendon mechanical properties deteriorate. Future studies by our laboratory will investigate potential strategies to improve patellar tendon autograft integration into bone using this model.

Relación de longitud entre tendón rotuliano y ligamento cruzado anterior: importancia clínico-quirúrgica / Relationship between length patellar tendon and anterior cruciate ligament: clinical-surgical importance

Objetivo: Correlacionar las dimensiones del Tendón Rotuliano y del Ligamento Cruzado Anterior de lamisma rodilla en cadáveres adultos para contribuir amejorar la técnica de reconstrucción en la plástica delligamento cruzado anterior.Materiales y métodos: Utilizamos en el estudio20 rodillas aisladas formalizadas al 10% sin identificación de sexo tomadas al azar de una población de 150rodillas. Se disecaron con técnica clásica levantando larótula desde proximal liberando el tendón cuadricipitalel cual fue medido con calibre digital lo mismo que elligamento cruzado anterior que fue medido en flexión de90º.Resultados: El presente estudio nos permite observar la diferencia de longitud que existe en todos loscasos entre ambos elementos en forma permanente, lalongitud promedio fue de 42,41 milímetros para el Tendón Rotuliano y de 32,38 milímetros para el LigamentoCruzado Anterior; esta diferencia anatómica es de 1,33milímetros a favor del Tendón Rotuliano promedio conrelación a todos los casos.Conclusión: este estudio nos indica que en las plásticas ligam entarias donde utilizan el Tendón Rotuliano se necesitaría indefectiblemente suplir el Tendón Rotuliano con injerto óseo para evitar el llamadoefecto “limpia parabrisa.

Objective: correlation between patellar tendon (PT) and Anterior Cruciate Ligament (ACL) of the sameknee in cadaveric adult patients and its contribution to improve the technique in ACL surgery reconstruction.Materials and Methods: from 150 knees without gender distribution we took 20 for study. The classic dissection technique, lifting the patella from proximal and clearing the cuadricipital tendon was used. The digitalcaliber of tendon was measured at 90 degrees flexion of the knee.Results: in all cases the difference between both structures was permanent; PT in average was 1,33mmlarger than ACL. Conclusions: in this study the permanent differencefounded show us the mandatory necessity to use bone graft in this kind of surgery in order to avoid the called wiper effect.

Intramedullary insertion of the patellar tendon.

This case represents a rare presentation of an intramedullary insertion of the patellar tendon in an otherwise healthy 8-year-old girl. To our knowledge no such phenomenon has previously been reported in the English literature.

Distalization of the patella during tibial callus distraction.

Consecutive distalization of the patella is described in two patients undergoing segmental transportation after high tibial corticotomy. Revision surgery with loosening and proximal reattachment of a portion of the patellar ligament bridging the callus distraction zone could re-establish the correct patellar position. Despite excellent callus formation after tibial corticotomy just below the tibial tuberositas, this procedure should be performed more distally as the fibers of the patellar tendon spread laterally and distally.