Medial Patellar Ligament Research Articles

FIXATION OF OSTEOCHONDRAL PATELLAR FRACTURE BY TRANSOSSEOUS SUTURE: REPORT OF TWO CASES

Objectives The article aims to explore two cases of osteochondral patellar fracture after acute dislocation, emphasizing the importance of appropriate treatment to prevent early progression to patellofemoral osteoarthritis. The study describes a surgical approach involving transosseous suture fixation and fibrin glue adjuvant, presenting it as a potential alternative over existing techniques. Methods Two patients (a 38 years-old male, and a 12 years-old female) with patellar osteochondral fracture due acute patellar dislocation were underwent surgical intervention. The procedure was performed by medial parapatellar arthrotomy and a transosseous suture fixation by high-strength sutures in the male and absorbable sutures in the female, plus use of fibrin glue as an adjuvant in both. Additionally, reconstruction of the medial patellofemoral ligament (MPFL) with the medial third of the patellar tendon was performed in the male and MPFL and medial patellar tibial ligament using hamstrings in the female. Results Postoperative follow-up revealed good clinical and radiographic outcomes. The patients exhibited complete symptom resolution, full ROM, patellar stability and completely cartilage healing on MRI at 3 and 9 months, respectively. The technique showed potential advantages, including simple reproducibility, low cost, and minimal postoperative complications. Conclusion Fixation of osteochondral patellar fracture by transosseous sutures combined with fibrin glue emerges as a reproducible, cost-effective technique with excellent clinical and radiological outcomes. The method displayed advantages over traditional implants, offering a potential alternative for surgeons. Despite the positive results in these cases, the limited literature calls for further research to confirm the technique superiority compared to isolated sutures and other available methods.

Anatomic physeal-sparing MPFL reconstruction in skeletally immature patients shows favourable outcomes at a minimum of 24-month follow-up.

Recurrent patellar dislocation is a prevalent orthopaedic issue among active paediatric and adolescent populations. Bony surgical procedures are not recommended in growing patients; therefore, the focus of surgery is on restoring the medial patellar ligaments, with different reconstructive techniques available. This retrospective case series focuses on the 2-year outcomes of medial patellofemoral ligament (MPFL) reconstruction in skeletally immature patients with open physis. Twenty-four consecutive patients with patellofemoral instability and open growth plates underwent anatomic MPFL reconstruction with a physeal-sparing technique. All subjects have had more than three episodes of true patellar dislocations. Preoperative radiographic examination included anteroposterior and lateral views to assess patella alta and limb alignment. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TT-TG) distance. The patients were questioned regarding complications and clinical outcomes using the visual analogue scale (VAS), Kujala and Paediatric International Knee Documentation Committee (Pedi-IKDC) score. Variables were evaluated using paired t test with significance at p < 0.05. The mean age at the time of operation was 13.04 years (9-16 years). The cohort was followed for a mean duration of 38.66 months (24-86 months). The mean time from injury to surgery was 50.45 days (16-80 days). No growth arrest, limb-length discrepancies or angular deformities were observed post-operatively during the whole follow-up period. No patellar re-dislocations were recorded throughout the study period. The VAS score improved significantly from 5.67 (4-8) to 1.88 (0-4) (p < 0.01). The Kujala score improved significantly from 64.67 (44-81) preoperatively to 87.58 (77-100) post-operatively (p < 0.01). The Pedi-IKDC also increased significantly from 58.81 (34.80-77.70) preoperatively to 90.64 (70.70-100) post-operatively (p < 0.01). The vast majority of patients (87.5%) returned to their pre-injury activity level. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant. Physeal-sparing MPFL reconstruction in children and adolescents yields excellent midterm results and allows patients to return to sports without redislocation of the patella. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant. IV: case series with no comparative group.

Collagen Fibril Morphological Study of Medial Patellar Ligament of Stifle Joint Affected with Patellar Luxation in Cattle

Background: Upward fixation of patella is common clinical malady in cattle due to extensive movement of stifle joint during the locomotory activity because of unknown etiology. However, at certain peak point (overstretching of ligament) or due to occupational trauma (wear and tear), ligament become flaccid and weak leading to patellar displacement and lameness. Patellar ligaments play crucial role in stifle joint movement and any functional or structural alterations in the ligaments can lead to acute to chronic lameness in cattle. The present study was carried out to evaluate the structural changes in collagen fibril material in medial patellar ligament in cattle suffering with patellar luxation. Methods: Tissue specimens of medial patellar ligament of normal (control animal) and affected cattle (luxation of patella) were harvested and preserved for scanning electron microscopy (SEM) and transmission electron microscopic (TEM) study as per standard procedure at RUSKA Laboratories, College of Veterinary Science, PVNRTVU, Rajendranagar, Hyderabad, India. Result: The incidence of medial patellar luxation was higher in females as compared to male cattle and the duration of lameness was between 3-12 months (7.35±0.56 months) characterized by dragging of toe, outward jerky movement of affected limb, extension of limb and change in appearance of gait during walk and flexion of fetlock. Scanning electron study of normal ligament showed dense, uniformly and compact arrangement of collagen fiber bundles with morphometric thickness was 3.66±0.58 µm. whereas in luxated patella cases, medial ligament showed derangement in collagen fiber bundles. The collagen fibers were arranged irregular and wavy with morphometric thickness of collagen was 2.58±0.03 µm. Electron microscopy of the normal ligament showed presence of thick collagen fiber bundles packed in dense and compact arrangement. Electron microscopy of affected ligament had degenerative changes of the fibers characterized by thin collagen fiber bundles which were loosely and disorganized arranged fibrils. The present study concludes that, luxation of patella was common locomotory disorders in cattle due to derangement in collagen fiber bundles with drastic reduction in thickness of collagen fibers, increased gap between two collagen fibers, broken and overlapping fiber bundles and surface of collagen fibers appeared irregular rough via scanning and electron microscopy analysis.

MPFL RECONSTRUCTION, USING FASCIA LATA AS AN AUTOGRAFT, AFTER FAILED PROXIMAL AND DISTAL PATELLOFEMORAL REALIGHMENT PROCEDURES. REPORT OF TWO CASES

Understanding all the technical features and functions associated with medial patellar ligament reconstruction (MPFL) with autograft will make restoration more effectual, limiting complications associated with its non-anatomical placement. We describe in this study the cases of two girls aged seven and thirteen who underwent successful MPFL reconstruction after failed proximal and distal patellofemoral realignment surgeries they had previously undergone to treat recurrent patellar dislocation. The modified Cincinnati and Kujala score were used for the preoperative and postoperative clinical evaluation of the two girls. In the final reassessment of the two girls, seven years post-operatively for the seven-year-old girl, and three years post-operatively for the thirteen-year-old girl, the modified Cincinnati score and the Kujala score were increased significantly. The restoration of the MPFL is a justified surgical method for an effective outcome of the reestablishment of patellar stability in skeletally immature patients who underwent less successful surgeries in the past.

Differences in collagen types in the semitendinosus, quadriceps, and patellar tendons: A report using samples from an 11-year-old patient

BackgroundThis study aimed to determine the differences in the proportions of types I and type III collagen in the semitendinosus tendon (ST), quadriceps tendon (QT), and patellar tendon (PT), which are frequently used as autografts for anterior cruciate ligament (ACL) reconstruction. MethodsOrthopedic surgeons diagnosed habitual dislocation of the left patella and surgically treated an 11-year-old boy. Medial patellofemoral ligament reconstruction, medial patellar tibial ligament reconstruction, and arthroscopic lateral release were performed simultaneously. Tissue samples obtained during treatment that were no longer necessary were used as samples for this study. The samples were fixed, paraffin-embedded, and immunostained for type I and type III collagen. Stained samples were observed under a confocal microscope and evaluated visually and quantitatively to determine the percentages of type I and type III collagen. ResultsVisually, the ST had a higher percentage of type III collagen than the PT and QT. The QT and PT were similar in appearance; both consisted mostly of collagen type I. Quantitative evaluation using images showed that the PT comprised 100% type I collagen. The QT comprised 1% type III collagen. The ST comprised 34% type III collagen. ConclusionIn this patient, the QT and PT had higher percentages of type I collagen, which is considered physically strong. Type III collagen, which is considered physically weak, was most common in the ST. These factors may be associated with the high re-injury rates after ACL reconstruction using the ST for physically immature patients.

The equine patellar ligaments and the infrapatellar fat pad – a microanatomical study

BackgroundInterpretation of patellar ligament (PL) ultrasonography may be difficult, as hypoechoic or heterogenous echogenicity are common findings. Verifying suspected disease of equine PLs by histopathology is also problematic as descriptions of normal PL vascularity and histology are scarce. The current study describes the PL and infrapatellar fat pad (IFP) vascular pattern from computed tomography scans of barium perfused normal equine specimens (n = 8; age 10 days to 18 years), as well as routine histology to serve as a reference for future investigations into PL pathology and IFP disease.ResultsThe PLs received a bipolar blood supply. Vascular architecture consisted of numerous distinct longitudinal vessels with several horizontal connections, which branched into extensive latticeworks of smaller vessels throughout the ligaments. Several vascular connections between the PLs and the IFP were identified. One distinct longitudinal vessel was seen entering each of the IFP lobes at the distocranial aspect, branching extensively into lobar vascular networks which anastomosed by several horizontal branches at the mid portion of the IFP where the two lobes merge. Histologically, there were large variations in PL interfascicular endotenon thickness, vascularity and fatty infiltration; these parameters increased with age for the intermediate and medial PL. Areas of metaplastic tenocytes / chondroid metaplasia were identified in all investigated adult medial PLs; in 2/7 in the intermediate PL and in 4/7 in the lateral PL. The adult IFP consisted of white unilocular adipose tissue, organized in lobules separated by thin connective tissue septa increasing in thickness towards the periphery and the distocentral aspect.ConclusionsThe equine PLs and IFP are highly vascularized structures with ample vascular connections suggestive of crosstalk. This, together with the large variation in PL endotenon thickness, vascularity and fatty infiltration, should be taken into consideration when assessing potential PL histopathology as these changes increase with age and are found in horses without clinical signs of stifle disease. Metaplastic tenocytes / chondroid metaplasia should be considered a normal finding throughout the medial PL and is not age dependent. The role of the equine IFP in stifle disease has yet to be elucidated.

Thermography Diagnosis of Medial Patellar Ligament Rupture in a Horse

Thermography Diagnosis of Medial Patellar Ligament Rupture in a Horse

The Efficacy of Platelet-Rich Plasma for Ligament Injuries: A Systematic Review of Basic Science Literature With Protocol Quality Assessment.

Background:Despite the existence of many clinical studies on platelet-rich plasma (PRP) interventions for ligamentous pathology, basic science consensus regarding the indications, mechanisms, and optimal composition of PRP for treating ligament injuries is lacking.Purpose:To (1) compare the efficacy of PRP in animal models of ligament injury with placebo and (2) describe the potential variability in PRP preparation using accepted classification systems.Study Design:Systematic review.Methods:The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Embase, and Ovid MEDLINE were queried in April 2020 for in vivo and in vitro basic science studies regarding PRP use for ligament injury. Study design, results, PRP composition, and analyzed cellular and molecular markers were extracted, and outcomes relative to control models were documented. Bias was assessed using the SYRCLE risk-of-bias tool.Results:Included were 43 articles (31 in vivo and 12 in vitro studies) investigating the anterior cruciate ligament/cranial cruciate ligament (n = 32), medial collateral ligament (n = 6), suspensory ligament (n = 3), patellar ligament (n = 1), and Hock ligament (n = 1). Platelet concentration was reported in 34 studies (77.3%); leukocyte composition, in 12 (27.3%); and red blood cell counts, in 7 (15.9%). With PRP treatment, 5 of 12 in vitro studies demonstrated significant increases in cell viability, 6 of 12 in gene expression, 14 of 32 in vivo studies reported superior ligament repair via histological evaluation, and 13 in vivo studies reported superior mechanical properties. Variability in PRP preparation methods was observed across all articles, and only 1 study reported all necessary information to be classified by the 4 schemes we used to evaluate reporting. Among the in vivo studies, detection and performance bias were consistently high, whereas selection, attrition, reporting, and other biases were consistently low.Conclusion:Conflicting data on the cellular and molecular effects of PRP for ligament injuries were observed secondary to the finding that included studies were heterogeneous, limiting interpretation across studies and the ability to draw meaningful conclusions. Clinical trials and any causal relationship between PRP use in ligament injuries and its potential for regeneration and healing should be pursued with caution if based solely on basic science data.

English

An 8-day-old female Shetland pony was referred to the Jeonbuk animal medical center for evaluation of bilateral hindlimb lameness. The foal had been severely lame in the both hind leg since birth. The luxation of the patella was confirmed on physical examinations. During the operation, extensive soft tissue damage and hemorrhage were observed around the medial patellar ligament. Lateral patellar luxation was surgically repaired using lateral release of the patella and medial imbrication of the joint capsule. Follow up revealed that lameness improved during postoperative period. It was concluded that patella luxation as a traumatic cause of lameness in foals can be corrected by surgical techniques successfully. Key words: Lateral patellar luxation, surgery, shetland pony, foal, stifle.

THE EXTENT OF MEDIAL QUADRICEPS TENDON FEMORAL LIGAMENT (MQTFL) PATELLAR AND QUADRICEPS ATTACHMENT: A PEDIATRIC CADAVERIC STUDY

Background:The most common modern procedure for medial patellar stabilization involves reconstruction of the medial patellofemoral ligament (MPFL) and involves reconstructed ligament attachment to the femur and patella. However, cases of patellar fracture have been reported, particularly in the smaller anatomy of the pediatric population, leading to further investigations of patella stabilizing structures. The medial quadriceps tendon femoral ligament has been identified as a separate structure, connecting the patella to the femur and playing a significant role in patella stability. Reconstruction of this ligament may serve a role in patellar stabilization similar to pedicled quadriceps tendon medial ligamentous reconstructions. The anatomy and relationship of the MQTFL attachment to the quadriceps tendon and proximal pole of the patella has not been described in pediatric specimens.Purpose:To determine the anatomical relationship and attachment of the medial quadriceps tendon femoral ligament (MQTFL) on the patella and quadriceps tendon.Methods:Six pediatric cadaveric knee specimens were dissected to identify the patellar and quadriceps attachment site of the MQTFL. Dissection was facilitated by lateral arthrotomy and identification of the MQTFL thickened fibers from the undersurface of the ligament.Results:Six specimens included patients a mean age of 6 years at time of patient death (three 10-year-old specimens, one 4-year-old, and one 2-month-old specimen). The MQTFL was identified in all specimens. As identified from the undersurface of the everted extensor mechanism, it was found to insert a mean distance of 10.5 mm (range 3.9 – 18.2) from the superior pole of the patella. The attachment distally along the edge of the bony patella measured a mean of 12.7 mm (range 5.4-19.4). Total patellar length, as measured from the posterior articular surface, was a mean of 24.5 mm (range 11.0-35.6). Attachment to the quadriceps tendon averaged 47% of total attachment to both the quadriceps tendon and patella; conversely, direct patellar measurement averaged 53%.Conclusion:This study provides quantitative anatomy to attachment of the MQTFL to the patella and quadriceps tendon. Precise knowledge of these structures will assist to more precisely define the complex relationship between stabilizing structures to the medial patellofemoral joint and assist in patella stabilization procedures, particularly in skeletally immature patients. A lower risk of patellar fracture may be one of the key benefits of this procedure, compared with MPFL reconstruction.FIGURESFigure 1:.View from the posterior surface (ie inside joint) following lateral arthrotomy. Note MQTFL attachment point in relation to the proximal extent of the cartilaginous articular surface.ReferencesFulkerson JP, Edgar C. Medial quadriceps tendon-femoral ligament: Surgical anatomy and reconstruction technique to prevent patella instability. Arthrosc Tech 2013;2:e125- e128.Joseph SM, Fulkerson JP. Medial Quadriceps Tendon Femoral Ligament Reconstruction Technique and Surgical Anatomy. Arthroscopy techniques. 2019 Jan 1;8(1):e57-64.Parikh SN, Wall EJ. Patellar fracture after medial patel- lofemoral ligament surgery: A report of five cases. J Bone Joint Surg Am 2011;93. e97(1-8)Dhinsa BS, Bhamra JS, James C, Dunnet W, Zahn H. Patella fracture after medial patellofemoral ligament reconstruction using suture anchors. Knee 2013;20:605- 608.Shah JN, Howard JS, Flanigan DC, Brophy RH, Carey JL, Lattermann C. A systematic review of complications and failures associated with medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Am J Sports Med 2012;40:1916-1923Tanaka MJ. The anatomy of the medial patellofemoral complex. Sports Med Arthrosc 2017;25:e8-e11.Kruckeberg BM, Chahla J, Moatshe G, et al. Quantitative and qualitative analysis of the medial patellar ligaments: An anatomic and radiographic study. Am J Sports Med 2017. 363546517729818LaPrade RF, Engebretsen AH, Ly TV, Johansen S, Wentorf FA, Engebretsen L. The anatomy of the medial part of the knee. J Bone Joint Surg Am 2007;89:2000- 2010.Mochizuki T, Nimura A, Tateishi T, Yamaguchi K, Muneta T, Akita K. Anatomic study of the attachment of the medial patellofemoral ligament and its characteristic relationships to the vastus intermedius. Knee Surg Sports Traumatol Arthrosc 2013;21:305-310.Nelitz M, Williams SR. Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft. Arthroscopy techniques. 2014 Apr 1;3(2):e303-8.

Acoustic radiation force impulse (ARFI) elastography of the stifle joint of healthy beagles

ABSTRACT The objective was to establish the reference standards for elastography of the main structures of the canine stifle joint. The medial meniscus, patellar and cruciate ligaments of thirty healthy beagles was evaluated by B-mode and ARFI elastography (n=60 joints). Analysis detected a positive correlation of the shear wave velocity (SWV) of structures according to age. Patellar ligament presented a gradual stiffness increase in relation to age, while medial meniscus and cruciate ligament were more rigid in puppies than in adults. However, greater stiffness of these structures was observed in elderly animals. Elasticity of each structure was evaluated according to gender and reproductive status. Females presented greater stiffness of all structures, with SWV differing 0.3 and 0.36m/s between genders. Only the medial meniscus was not stiffer in neutered animals when compared to intact animals, differing only 0.02m/s in menisci and 0.4 to 0.47m/s in ligaments between groups. These findings corroborate with literature data that states a higher prevalence of ligament insufficiency in elderly dogs, females and neutered animals. It was concluded that ARFI elastography of the canine stifle joint is feasible and its application can be potentially effective in early diagnosis of ligament and meniscal changes.

Kinematic evaluation of isolated and combined medial patellofemoral and patellotibial ligament reconstruction to address lateral patellar instability

Objectives:The roles of the medial patellofemoral and patellotibial ligaments in patellofemoral kinematics have been previously reported. However, the effect of isolated and combined surgical reconstruction of these ligaments to restore native patellofemoral kinematics is not well understood. The purpose of this study was to determine the isolated and combined effects of medial patellofemoral and patellotibial ligament deficiency and reconstruction on patellofemoral kinematics.Methods:Sixteen matched-paired female, fresh-frozen, cadaveric knee specimens with a mean age of 53.5 years (range, 26-65) were used. Specimens were tested in five conditions; 1) intact, 2) MPFL or MPTL cut, 3) MPFL and MPTL combined cut, 4) MPFL or MPTL reconstruction, and 5) MPFL and MPTL combined reconstruction. Dynamic testing was performed by taking the knees through range of motion from 0° to 90° of knee flexion at 60 mm/min using a dynamic tensile testing machine by applying a force through the quadricep tendon. Following dynamic testing, knees were tested statically using a lateral load of 45 N applied to the patella at 0°, 30°, 60°, and 90° of flexion. In both dynamic and static loading tests, a motion capture system detected patellar position for each testing state to distinguish changes in patellar kinematics. Linear mixed effects modeling was performed to compare testing states.Results:Isolated MPFL deficiency created the greatest lateral translation of the patella at all knee flexion angles (p<0.001). MPTL deficiency alone did not create significant patella instability (p=0.68 or greater), but further increased instability when the MPFL was deficient (p<0.001). Isolated MPFL and combined MPFL and MPTL reconstruction decreased lateral patella translation (p<0.001). Native patella tracking was best recreated with combined ligament reconstruction while MPFL reconstruction alone over constrained the patella in extension and under constrained in flexion.Conclusions:The MPFL plays the greatest role in medial patellar stability, but the MPTL appears to have a large influence on patella tracking. The MPTL may be most important in preventing patellofemoral osteoarthritis following patella dislocation. Further investigation is needed to evaluate patellofemoral contact pressure following medial patellar ligament reconstruction.

Cross-anatomical, radiographic and computed tomographic study of the stifle joint of donkeys (Equus africanus asinus).

The present investigation was conducted to provide a full anatomical description of the stifle joint of donkeys using 3D computed tomography imaging technique, in addition to the classic anatomical methods, such as radiography and cross-anatomical sectioning. The radiography and CT imaging of stifle joint were interpreted in comparison with cross-sectional anatomical sections. Volume-rendering reconstruction techniques (3D-CT) were used to describe the anatomical structure of stifle joint. The used twelve adult healthy donkeys were free from any musculoskeletal disorders. Four donkeys were used for the gross anatomical observations, four for CT and radiography and two live animals for determination the site of injections. The results of this study revealed that the complex stifle joint was formed from three joints: femorotibial, femoropatellar and proximal tibiofibular. The articular surfaces were described for each joint, and the synovial layer of the articular capsule formed three main joint sacs: femoropatellar, medial femorotibial and lateral femorotibial sacs. The ligaments of stifle joint were recorded, and meniscal ligaments included cranial and caudal ligaments of medial and lateral menisci and meniscofemoral ligament of lateral meniscus. The cruciate ligaments were also described and they included the cranial and caudal cruciate ligaments, while the patellar ligament included the medial, middle and lateral patellar ligaments. The arterial supply and the site of injection of the stifle joint were described. In conclusion, the 3D reconstruction CT provided well-defined baseline reference image for the stifle joint of donkeys for anatomist, radiologist, surgeons and researchers.

Método para la reconstrucción del ligamento patelofemoral medial utilizando el tendón del cuádriceps: descripción de la técnica y resultados

BackgroundPatellar instability and recurrent dislocation is a prevalent disorder in children and adolescents that require surgical repair of the medial patellar femoral ligament (MPFL), paying particular attention in preserving the open growth plates in this population. MethodsWe describe a modified method for reconstruction of the medial patellofemoral ligament using an autograft from the quadriceps tendon, which is attached with anchor sutures to the epiphysial isometric point of the MPFL insertion. Since 2012, this technique has been used in pediatric patients in our institution; here, we present the long-term results of this cohort. ResultsWe have used this technique in 5 patients with patellar instability with recurrent patellar dislocation with a median postsurgical follow-up time of four years (range 2-5 years). The median preoperative Insall–Salvati ratio was 1.41. The median Kujala score before and after surgery during the last evaluation was 76.5 (range 34-100) and 98.5 (range 75-100), respectively. No cases of redislocation or episodes of subluxation were present during the follow-up. One patient presented West syndrome which made difficult pre and postoperative objective assessment; however, his results were satisfactory. DiscussionThis modified method constitutes an alternative technique of graft fixation, that in our experience, provides satisfactory results, with patellar stability caused by fixed graft tension. In the operated patients, no recurrences nor complications have been present.

Histomorphological Evaluation of Medial Patellar Ligament Affected with Upward Luxation of Patella in Cattle

Histomorphological Evaluation of Medial Patellar Ligament Affected with Upward Luxation of Patella in Cattle

Less iatrogenic soft-tissue damage utilizing robotic-assisted total knee arthroplasty when compared with a manual approach: A blinded assessment.

ObjectivesThe use of the haptically bounded saw blades in robotic-assisted total knee arthroplasty (RTKA) can potentially help to limit surrounding soft-tissue injuries. However, there are limited data characterizing these injuries for cruciate-retaining (CR) TKA with the use of this technique. The objective of this cadaver study was to compare the extent of soft-tissue damage sustained through a robotic-assisted, haptically guided TKA (RATKA) versus a manual TKA (MTKA) approach.MethodsA total of 12 fresh-frozen pelvis-to-toe cadaver specimens were included. Four surgeons each prepared three RATKA and three MTKA specimens for cruciate-retaining TKAs. A RATKA was performed on one knee and a MTKA on the other. Postoperatively, two additional surgeons assessed and graded damage to 14 key anatomical structures in a blinded manner. Kruskal–Wallis hypothesis tests were performed to assess statistical differences in soft-tissue damage between RATKA and MTKA cases.ResultsSignificantly less damage occurred to the PCLs in the RATKA versus the MTKA specimens (p < 0.001). RATKA specimens had non-significantly less damage to the deep medial collateral ligaments (p = 0.149), iliotibial bands (p = 0.580), poplitei (p = 0.248), and patellar ligaments (p = 0.317). The remaining anatomical structures had minimal soft-tissue damage in all MTKA and RATKA specimens.ConclusionThe results of this study indicate that less soft-tissue damage may occur when utilizing RATKA compared with MTKA. These findings are likely due to the enhanced preoperative planning with the robotic software, the real-time intraoperative feedback, and the haptically bounded saw blade, all of which may help protect the surrounding soft tissues and ligaments.Cite this article: Bone Joint Res 2019;8:495–501.

New surgical technique for medial patellar ligament splitting for treatment of upward fixation of patella in cattle and donkeys

A new medial patellar ligament splitting technique in cattle and donkeys is presented. It has been successfully applied on thirteen alive animals affected with permanent upward fixation of patella (UFP). The technique is simple, quick and easily applicable. In contrast to other medial patellar desmotomy techniques; the present approach is less invasive, the skin at the surgical site is not incised but punctured, the pericapsular fat and joint capsule are not invaded. Minimal tissue invasiveness limits the infection of surgical site, minimises bleeding and decreases their related postoperative consequences.

New approach for medial patellar ligament splitting for treatment of upward fixation of patella

A new medial patellar ligament splitting technique in cattle and donkeys is presented. It has been successfully applied on thirteen alive animals affected with permanent upward fixation of patella (UFP). The technique is simple, quick and easily applicable. In contrast to other medial patellar desmotomy techniques the present approach is less invasive, the skin at the surgical site is not incised but punctured, the pericapsular fat and joint capsule are not invaded. Minimal tissue invasiveness limits the infection of surgical site, minimizes bleeding and decreases their related postoperative consequences.

Biomechanical Evaluation of the Medial Stabilizers of the Patella

Background: Quantification of the biomechanical properties of each individual medial patellar ligament will facilitate an understanding of injury patterns and enhance anatomic reconstruction techniques by improving the selection of grafts possessing appropriate biomechanical properties for each ligament. Purpose: To determine the ultimate failure load, stiffness, and mechanism of failure of the medial patellofemoral ligament (MPFL), medial patellotibial ligament (MPTL), and medial patellomeniscal ligament (MPML) to assist with selection of graft tissue for anatomic reconstructions. Study Design: Descriptive laboratory study. Methods: Twenty-two nonpaired, fresh-frozen cadaveric knees were dissected free of all soft tissue structures except for the MPFL, MPTL, and MPML. Two specimens were ultimately excluded because their medial structure fibers were lacerated during dissection. The patella was obliquely cut to test the MPFL and the MPTL-MPML complex separately. To ensure that the common patellar insertion of the MPTL and MPML was not compromised during testing, only one each of the MPML and MPTL were tested per specimen (n = 10 each). Specimens were secured in a dynamic tensile testing machine, and the ultimate load, stiffness, and mechanism of failure of each ligament (MPFL = 20, MPML = 10, and MPTL = 10) were recorded. Results: The mean ± SD ultimate load of the MPFL (178 ± 46 N) was not significantly greater than that of the MPTL (147 ± 80 N; P = .706) but was significantly greater than that of the MPML (105 ± 62 N; P = .001). The mean ultimate load of the MPTL was not significantly different from that of the MPML (P = .210). Of the 20 MPFLs tested, 16 failed by midsubstance rupture and 4 by bony avulsion on the femur. Of the 10 MPTLs tested, 9 failed by midsubstance rupture and 1 by bony avulsion on the patella. Finally, of the 10 MPMLs tested, all 10 failed by midsubstance rupture. No significant difference was found in mean stiffness between the MPFL (23 ± 6 N/mm2) and the MPTL (31 ± 21 N/mm2; P = .169), but a significant difference was found between the MPFL and the MPML (14 ± 8 N/mm2; P = .003) and between the MPTL and MPML (P = .028). Conclusion: The MPFL and MPTL had comparable ultimate loads and stiffness, while the MPML had lower failure loads and stiffness. Midsubstance failure was the most common type of failure; therefore, reconstruction grafts should meet or exceed the values reported herein. Clinical Relevance: For an anatomic medial-sided knee reconstruction, the individual biomechanical contributions of the medial patellar ligamentous structures (MPFL, MPTL, and MPML) need to be characterized to facilitate an optimal reconstruction design.

Technique of Tibial Tuberosity Transposition and Advancement (TTTA) With Use of TTA-Maquet Cage-Only in Dog

Background: The most common conditions that compromise the stifle joint in dogs are medial patellar luxation (MPL) and cranial cruciate ligament (CCL) rupture. Surgical procedures are usually indicated for the treatment of these diseases. One ordinary technique for the treatment of MPL is the tibial tuberosity transposition, and one prominent technique for CCL rupture is the tibial tuberosity advancement. These techniques can be associated in one surgical procedure called tibial tuberosity transposition and advancement (TTTA) for the simultaneous treatment of both stifle diseases. The aim of this study is to report the surgical treatment of a dog with MPL and CCL rupture affecting the same joint by the TTTA technique with the use of a TTA-Maquet cage-only.Case: A 3-year-old Pitbull dog weighing 39 kg was attended at Veterinary Hospital with a history of marked lameness in the left pelvic limb. The orthopedic examination showed positive results for cranial drawer motion and tibial compression tests, and a complete CCL rupture was diagnosed. The presence of patellar luxation was evaluated by manual pressure on the patella, and grade 3 of MPL was diagnosed. Both conditions were affecting the same stifle joint. In addition, survey radiographs of the affected joint were performed. Surgical treatment was indicated by the TTTA technique. Radiographic measurements were taken to calculate the cranial tibial tuberosity advancement by the tibial plateau and the common tangent methods, and a titanium TTA-Maquet cage-only of 10.5 x 20.0 mm was selected. Linear osteotomy was performed on the tibial tuberosity with the aid of an oscillating saw, based on the Maquet hole technique. The tibial tuberosity was carefully displaced cranially and the cage was inserted at the site of osteotomy. The cage ears were molded on the tibial surface and fixed with 2.4 mm self-tapping cortical screws. At the moment of the cage attachment to the tibial tuberosity, orthopedic washers of 2 mm wide were placed between the cranial ears of the cage and the tibial tuberosity, thus promoting a lateral transposition of the tibial tuberosity. The patient was maintained in the early postoperative period with Robert Jones bandage, and with antibiotic, analgesic and anti-inflammatory drugs. On the second day after the procedure partial limb support with presence of mild lameness was observed. At three months postoperatively, the animal had no claudication and MPL was corrected. The radiographic examination showed the proper process of bone repair at the osteotomy site. In the clinical evaluation performed at one year after surgery the patient was in good condition without lameness and with proper limb support and muscular gain.Discussion: The studies that evaluated the association of tibial tuberosity transposition and tibial tuberosity advancement techniques (TTTA) for the simultaneous treatment of MPL and CCL rupture demonstrated that this is a viable and effective procedure. In this report, the accomplishment of tibial osteotomy based on the Maquet hole and the advancement of the tibial tuberosity with the TTA-Maquet cage-only allowed the dynamic stabilization of the CCL deficient stifle and the early use of the affected limb. In addition, the TTTA technique proved to be effective for the correction of grade 3 of MPL in a large dog, allowing adequate recovery of the limb function without complications during a one year evaluation period.