Anterior Fibers Research Articles

Biomechanical Changes to the Hindfoot After Zadek Osteotomy.

Insertional Achilles tendinopathy (IAT) is a common source of heel pain in active adults and athletes. The Zadek osteotomy (ZO) is a calcaneal dorsal closing wedge osteotomy that has demonstrated clinical success as a treatment for IAT, purported to favorably improve tendon mechanics, decrease impingement, and decrease pressure within the retrocalcaneal bursa. The present study aims to evaluate the biomechanical effects of ZO on Achilles strain, position of the Haglund prominence relative to the Achilles insertion, and retrocalcaneal pressure. The ZO was performed on 10 fresh-frozen foot and ankle mid tibia-fibula cadaveric specimens. An osteotomy was performed using a 1-cm dorsal closing wedge procedure secured with a 7.0 mm cannulated screw. Point pressure sensor catheters and differential variable reluctance transducers were used to measure the retrocalcaneal pressure and Achilles strain, respectively, pre- and postosteotomy. Paired t-tests were utilized to detect statistical differences (P < .05). After the ZO, the Haglund prominence was translated 9.9 mm anteriorly with respect to the insertion of the Achilles (P < .05) and the Achilles tendon insertion was translated 3.4 mm proximally (P < .05). The ratio of calcaneal length to greater tuberosity length, the X/Y ratio, increased from 2.56 to 3.52 with the osteotomy (P < .05). At maximum dorsiflexion, retrocalcaneal pressure decreased from 117 to 66 mm Hg (44%, P = .018). The Achilles strain changed from 0.00362 to 0.00436 in the anterior fibers (P = .484) and changed from 0.00467 to 0.00283 in the posterior fibers (P = .088). Biomechanical testing in a cadaveric model demonstrates that the ZO decreased retrocalcaneal pressure, shifted the Achilles tendon insertion proximally, increased the X/Y ratio of the calcaneus, and did not significantly change the strain of the Achilles tendon. Despite the clinical success demonstrated in recent literature, there are no biomechanical studies describing the effect of the ZO on the biomechanics of the hindfoot, and the mechanism of symptom relief of the ZO for IAT is not well understood. The present study measures two potential ZO effects relative to Haglund prominence by measuring retrocalcaneal pressure and displacement of the Achilles tendon with respect to the Haglund prominence, and measures one ZO effect relative to calcification of the tendon by measuring the Achilles tendon strain.

Differential neuromotor control of the vertical and longitudinal genioglossus muscle fibers: An overlooked tongue retractor

IntroductionThe genioglossus (GG) is known to be the main tongue protrusor, and therefore plays a major role in breathing. However, due to the fan shape of the GG fibers, it could be assumed that contraction of the anterior fibers of the GG do not cause tongue protrusion. In this study, we examined the effect of contraction of the anterior-vertical fibers of the GG (GGV) on the tongue and their EMG activity during wakefulness and sleep. The findings were compared to those of the longitudinal fibers (GGL), which, based on their orientation, are responsible for tongue protrusion. MethodsFine-wire electrode pairs were placed into the GGV and GGL in 11 patients with untreated OSA. Movement of the tongue during electrical stimulation at each site was videoed. The same electrodes were used to record EMG from both sites during respiratory stimulation by inspiratory loading and CO2 rebreathing during wakefulness. During sleep, repetitive flow limitation events were induced with low-level CPAP to augment GG activity. ResultsIn all participants, electrical stimulation of GGL and GGV protruded and retracted the tongue, respectively. Respiratory stimulation increased GG activity, but GGV reached only 39 % and 23 % of peak GGL activity during high resistive loading and PCO2 of 65 mmHg, respectively. Flow limitation during sleep increased GGL to levels that were considerably higher than awake baseline, but GGV activity remained tonic or with minimal phasic activity, reaching on average 15 % of GGL peak activity. ConclusionsOur electrical stimulation findings indicate that GGV is a tongue retractor and depressor. Tongue stimulation for OSA should avoid this area. The EMG results demonstrate that the anterior part of the GG is controlled very differently from the longitudinal protrusive fibers. The GGV responses are similar to those previously found in tongue retractors and peri-pharyngeal muscles other than the GG, in which diminished activation during sleep is likely to be involved in the failure of increasing GGL activity to alleviate flow limitation.

Anterior Slope–Modifying Osteotomies Alter the Length Change Behavior of the Superficial Medial Collateral Ligament: A Biomechanical Study

Background: Increased tibial slope has been shown to lead to higher rates of anterior cruciate ligament graft failure. A slope-decreasing osteotomy can reduce in situ anterior cruciate ligament force and may mitigate this risk. However, how this procedure may affect the length change behavior of the medial ligamentous structures is unknown. Purpose/Hypothesis: The purpose of this study was to examine the effect of anterior slope–modifying osteotomies on the medial ligamentous structures. It was hypothesized that (1) decreasing the tibial slope would lead to shortening of the superficial medial collateral ligament (sMCL), (2) while the fibers of the posterior oblique ligament (POL) would be unaffected. Study Design: Descriptive laboratory study. Methods: Eight fresh-frozen cadaveric knee specimens underwent anatomic dissection to precisely identify the medial ligamentous structures. The knees were mounted in a custom-made kinematics rig with the quadriceps muscle and iliotibial tract loaded. An anterior slope–modifying osteotomy was performed and fixed using an external fixator, which allowed modification of the wedge height between −15 and +10 mm in 5-mm increments. Threads were mounted between pins positioned at the anterior, middle, and posterior parts of the tibial and femoral attachments of the sMCL and POL. For different tibial slope modifications, length changes between the tibiofemoral pin combinations were recorded using a rotary encoder as the knee was flexed between 0° and 120°. Results: All sMCL fiber regions shortened with slope reduction (P < .001) and lengthened with slope increase (P < .001), with the anterior sMCL fibers more affected than the posterior sMCL fibers. A 15-mm anterior closing-wedge high tibial osteotomy (ACWHTO) resulted in a 6.9% ± 3.0% decrease in the length of the anterior sMCL fibers compared with a 3.6% ± 2.3% decrease for the posterior sMCL fibers. A 10-mm anterior opening-wedge high tibial osteotomy (AOWHTO) increased anterior sMCL fiber length by 5.9% ± 2.3% and posterior sMCL fiber length by 1.6% ± 1.0%. The POL fibers were not significantly affected by a slope-modifying osteotomy. Conclusion: Tibial slope–modifying osteotomies changed the length change pattern of the sMCL such that an AOWHTO increased whereas an ACWHTO decreased the sMCL strain. This effect was most pronounced for the anterior fibers of the sMCL. The length change pattern of the POL remained unaffected by slope-modifying osteotomy. Clinical Relevance: Surgeons should be aware that anterior tibial slope–modifying osteotomies affect the biomechanics of the sMCL. After an extensive ACWHTO, patients may develop a medial or anteromedial instability, while an AOWHTO may overconstrain the medial compartment.

The natural course of an iridoschisis: A case report.

Iridoschisis is a rare ophthalmological disorder that presents with the separation of the anterior fibers of the iris from the posterior ones at the level of the stromal layer. Fibers resulting from the disintegration of the anterior iris layers can be encountered in the anterior chamber of the affected eyes. This condition mostly affects females and has been associated with both open-angle and angle-closure glaucoma. The pathogenesis has not been clarified yet, and the treatment is still a matter of discussion. We want to contribute to the understanding of the pathogenesis and natural course of the disease as well as to document with multimodal imaging a new case of this very rare disease. We present a case of a 71-year-old woman affected by iridoschisis in both eyes followed by 3 consecutive visits every 4 months. We performed an extensive ophthalmologic examination, including gonioscopy, endothelial cell microscopy, and optical coherence tomography of the anterior segment. In our report, we documented a possible natural course of iridoschisis, characterized by an acute worsening followed by a phase of stability, and formulated some hypotheses on the pathogenesis of this rare disease.

Gastrocnemius Strain: A Case Study

Gastrocnemius Strain is a painful condition of partial tearing of the medial belly of the gastrocnemius, caused by overstretching the muscle by concomitant ankle dorsiflexion and full knee extension. Contributory factors are muscle fatigue and degenerative changes [1]. The purpose of the case study is to present a case of Gastrocnemius Strain, who underwent physiotherapy department. The 35 years male was having pain in the left calf muscle for last eight days. According to the patient the pain started while running in the field for practicing for an upcoming sports event. He felt sudden acute pain in the left leg, followed by swelling after he placed his left heel on the field. He went to consult a physiatrist in a private hospital nearby. During examination, in clinic there was swelling, tenderness around the middle &amp; lower part of left Gastrocnemius muscle. There was increase pain in the leg during dorsiflexion of left foot, both active &amp; passive. He was unable bear full weight on the affected limb. Measurement of right &amp; left Gastrocnemius muscle was 38 cm &amp; 40 cm respectively, from 8 cm below tip of patella. The Thompson squeeze test was negative though it was painful. He was walking in non-weight bearing pattern using walker. M.R.I report suggested, there was fluid collection in left calf muscle, between Soleus &amp; medial head of Gastrocnemius, most prominent at the myotendinous junction. There was also tear with oedema in anterior fibres of left mid &amp; distal part of lateral head of Gastrocnemius &amp; anterior fibres of distal part of medial head of Gastrocnemius. The patient was treated with low-level laser therapy for 15 sittings &amp; was advised to apply Cryotherapy followed by crepe bandage application. After completion of treatment, there was minimum tenderness or pain in the affected area. The patient was able to bear full weight on the left limb. He was advised to continue exercises for strengthening Gastrocnemius &amp; Soleus muscle at home as demonstrated. Pain was measured using V.A.S on the first day before &amp; last day after treatment. Keywords: Gastrocnemius Strain, low-level laser therapy, clinical case, calf muscle injury, Cryotherapy..

The deltoid ligament is constantly formed by four fascicles reaching the navicular, spring ligament complex, calcaneus and talus.

The medial collateral ligament of the ankle, or deltoid ligament, can be injured in up to 40% of patients who sustain an ankle inversion sprain. Reporting injuries of the deltoid ligament is not easy due to confusion in the current anatomical descriptions, with up to 16 fascicles described, with variable frequencies. The purpose of this study was to clarify the anatomy of the deltoid ligament. Thirty-two fresh-frozen ankle specimens were used for this study. Careful dissection was undergone until full visualization of the deltoid ligament was achieved and measurements taken. The deltoid ligament was found to have four constant fascicles in two layers. The superficial layer consists of the tibionavicular, tibiospring and tibiocalcaneal fascicles, while the deep layer consists of the tibiotalar fascicle. Measurements of these fascicles are given in detail. The tibiotalar fascicle and the anterior part of the tibionavicular fascicle were found to be intra-articular structures. The deltoid ligament has a constant number of fascicles divided into a superficial and a deep layer. This clarification of the anatomy and terminology of the deltoid ligament and its fascicles will help clinical view, diagnosis and (interdoctor)communication and treatment. The ligamentous fibres of the deep layer, as well as the anterior fibres of the superficial layer (tibionavicular fascicle) are intra-articular, which could negatively impact its healing capacity, explaining chronicity of these types of injuries. Not applicable (cadaveric study).

Novel superior oblique anterior fiber plication with or without adjustable sliding knot for extorsion

PurposeTo report a novel surgical technique to correct excyclotropia, consisting of a superior oblique anterior fibers plication (SOAFP) with or without a hemihangback anterior knot, allowing access for postoperative adjustment. MethodsA retrospective interventional case series was conducted. Fourteen patients, 21-92 years of age, underwent SOAFP (18 eyes, 14 eyes on adjustable), at the Mayo Clinic in Rochester, Minnesota. SOAFP was the only procedure performed in 12 eyes; in 6 it was performed in conjunction with up to four horizontal rectus muscle recession, resection, and/or plication. Ocular alignment was assessed with prism and alternate cover and double Maddox rod tests; preoperatively, at initial and final (closest to 6-8 weeks) postoperative visits. ResultsPreoperative torsion ranged from 2° to 30° of extorsion (mean, 10.14 ± 7.01). A SOAFP of 2–30 mm (mean, 8.93 ± 5.63) was performed. At the initial postoperative examination, mean intorsional shift was 11.18 ± 7.37, accounting for 1.86° ± 1.04° of correction per millimeter of plication. Three eyes were adjusted after the initial visit to obtain a stronger plication effect targeting of 5° intorsion. At the final visit, 61 ± 23 days postoperatively, mean extorsion was 1.21° ± 2.29°, ranging from 5° of extorsion to 3 of intorsion. Mean final intorsional shift was 9.14 ± 7.53°, accounting for a 1.16 ± 0.50° of correction per millimeter of plication. Of our 14 patients, 13 had improvement in diplopia. ConclusionsIn our study cohort, SOAFP allowed for targeted and easily adjustable correction of extorsion.

Selective plication and grading of plication for correction of torsion in superior oblique palsy

Abstract: Acquired palsy of the trochlear nerve has been associated with closed-head injuries. We report the case of a 33-year-old male patient, who presented with complaints of torsional diplopia in the straight gaze which increased in the down gaze following head trauma. After a detailed ophthalmic evaluation, the patient was diagnosed with bilateral superior oblique (SO) palsy causing torsional diplopia. To counteract excyclotorsion, we have plicated the anterior one-third of the fibers of the SO in both eyes. Postoperatively, the patient was diplopia free and orthophoric, which maintained up to 3-month follow-up. Correction of excyclotorsion by selective plication of anterior fibers of the SO has already been reported in literature. However, the amount of plication to be performed for various degrees of torsion has not been appropriately described in the previously reported articles. We aim to improve the efficacy of plication anterior fibers of the SO by objective gradation.

The Anterior Fibers of the Superficial MCL and the ACL Restrain Anteromedial Rotatory Instability

Background: There is limited knowledge about how the anterior cruciate ligament (ACL) and capsuloligamentous structures on the medial side of the knee act to control anteromedial rotatory knee instability. Purpose: To investigate the contribution of the medial retinaculum, capsular structures (anteromedial capsule, deep medial collateral ligament [MCL], and posterior oblique ligament), and different fiber regions of the superficial MCL to restraining knee laxity, including anteromedial rotatory instability. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic testing system in a position-controlled mode. Loads of 10 N·m valgus rotation, 5 N·m tibial external rotation, 5 N·m tibial internal rotation, and 134 N anterior tibial translation in 5 N·m external rotation were applied at different flexion angles. The motion of the intact knee at 0° to 120° of flexion was replicated after sequential excision of the sartorial fascia; anteromedial retinaculum; anteromedial capsule; anterior, middle, and posterior fibers of the superficial MCL; the deep MCL; the posterior oblique ligament; and the ACL. The reduction in force/torque indicated the contribution of each resected structure to resisting laxity. A repeated-measures analysis of variance with a post hoc Bonferroni test was used to analyze the relative force and torque changes from the intact state. Results: The superficial MCL was the most important restraint to valgus rotation from 0° to 120° and provided the largest contribution to resisting external rotation between 30° and 120° of knee flexion, gradually increasing from 25.2% ± 7.4% at 30° to 36.9% ± 15.4% at 90°. The posterior oblique ligament contributed significantly to resisting valgus rotation only in extension (17.2% ± 12.1%) but was the major restraint to internal rotation at 0° (46.7% ± 13.1%) and 30° (30.4% ± 17.7%) of flexion. The sartorial fascia and anteromedial retinaculum resisted ER at all knee flexion angles (P < .05) and was the single most important restraint in the extended knee (19.5% ± 11%). The capsular structures (anteromedial capsule and deep MCL) had a combined contribution of 20% ± 11.5% at 0° and 23.4% ± 10.5% at 120° of knee flexion but were less important from 30° to 90°. The ACL was the primary restraint to anterior tibial translation in external rotation between 0° and 60° of flexion (50.2% ± 16.9% at 30°), but the superficial MCL was more important at 90° to 120° of knee flexion (36.8% ± 16.4% at 90°). The anterior, middle, and posterior regions of the superficial MCL contributed differently to the simulated laxity tests. The anterior fibers were the most important part of the superficial MCL in resisting external rotation and combined anterior tibial translation in external rotation. Conclusion: The superficial MCL not only was the primary restraint to valgus rotation throughout the range of knee flexion but also importantly contributed to resisting anterior tibial translation in external rotation, particularly in deeper flexion in the cadaveric model. The anterior fibers of the superficial MCL are the most important superficial MCL fibers in resisting anterior tibial translation in external rotation. This study suggests that a medial reconstruction that reproduces the function of the posterior MCL fibers and posterior oblique ligament may not best control anteromedial rotatory instability. Clinical Relevance: Based on these data, there is a need for an individualized medial reconstruction to address different types of medial injury patterns and instabilities.

Rotational ankle instability: A current concept review.

Ankle sprains are extremely common. It is important to have a clear insight of the course of recovery after such injury to evaluate the effective strategies to guide management decisions, and understand the potential risk factors involved in the development of chronic problems and recurrent ankle sprains. When a prompt diagnosis is not formulated, ligament tears can remain untreated, and chronic ankle instability can result after acute lateral or medial ankle sprain. When the medial ligament complex (MLC), in particular the anterior fascicle of the deltoid ligament, is involved, rotational ankle instability (RAI) can develop. Generally, a tear of the anterior fibres of the MCL accompanied by anterior talofibular ligament (ATFL) insufficiency has been associated with RAI, while injury of the intermediate fibres of the MLC has been associated with medial ankle instability (MAI). Conservative management is the first line of treatment, with surgery reserved for special cases or if rehabilitation has failed. Regarding surgery, several options are available, including anatomic repair, anatomic reconstruction, and tenodesis procedures. Ankle arthroscopy is increasingly used to address ligament insufficiency and to identify and treat intra-articular pathologies. Repair of MLC tears by an arthroscopic all-inside procedure is effective in both MAI and RAI.

Association of activities of daily living and cognitive function with thickness of the upper extremity muscles in children and adults with cerebral palsy

We examined the association of activities of daily living (ADL) and cognitive function with the upper extremity muscle thickness and upper extremity range of motion (ROM) and spasticity in children and adults with cerebral palsy (CP). The subjects were 20 children and adults with CP. The ADL performed using the upper extremities and cognitive function were assessed using the self-care domain of the Pediatric Evaluation of Disability Inventory (PEDI) and the full-scale intelligence quotient (FSIQ) of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV), respectively. The WISC-IV was assessed in only seven of 20 subjects able to undergo evaluation. The thickness of the upper extremity muscles was measured using an ultrasound imaging device. Moreover, ROM and spasticity of the upper extremities were assessed using the Modified Ashworth Scale (MAS). Manual manipulation ability was also assessed using the Manual Ability Classification System (MACS). Stepwise regression analysis revealed that the extensor digitorum muscle thickness and MACS level were significant and independent factors of self-care in the PEDI. Partial correlation analysis with MACS level and age as control variables showed that the FSIQ of the WISC-IV was significantly associated with the thickness of the anterior fibers of the deltoid and flexor digitorum superficialis muscles. Reduced ADL performed using the upper extremities is associated with decreased extensor digitorum muscle thickness rather than ROM and spasticity of the upper extremities in children and adults with CP.

3D Modeling of the Crystalline Lens Complex under Pseudoexfoliation.

Pseudoexfoliation, one of the most frequent crystalline lens complex disorders, is prevalent in up to 30% of individuals older than 60 years old. This disease can lead to severe conditions, such as subluxation or dislocation of the lens, due to the weakening of the zonules. The goal for the present study was to understand the relevant biomechanical features that can lead to the worsening of an individual’s visual capacity under pseudoexfoliation. To this end, finite element models based on a 62-year-old lens complex were developed, composed by the capsular bag, cortex, nucleus, anterior, equatorial, and posterior zonular fibers. Healthy and pseudoexfoliative conditions were simulated, varying the location of the zonulopathy (inferior/superior) and the degenerated layer. The accommodative capacity of the models with inferior dialysis of the zonular fibers was, on average, 4.7% greater than for the cases with superior dialysis. If the three sets of zonules were disrupted, this discrepancy increased to 14.9%. The present work provides relevant data to be further analyzed in clinical scenarios, as these models (and their future extension to a wider age range) can help in identifying the most influential regions for the reduction of the visual capacity of the lens.

A Fiber Dissection Study of the Anterior Commissure: Correlations with Diffusion Spectrum Imaging Tractography and Clinical Relevance in Gliomas.

The anterior commissure, which connects bilateral temporal lobes and olfactive areas, remains elusive in many aspects of its structure and functional role. To comparatively describe anatomical details of the anterior commissure using cadaveric fiber dissection (FD) and diffusion spectrum imaging (DSI) thus refining our knowledge of the tract and exploring its clinical relevance in glioma migration. Twelve normal postmortem hemispheres were treated with Klingler's method and subjected to FD with medial, inferior, and lateral approaches. The FD findings were correlated with DSI tractography results. To illustrate the clinical relevance, two patients with recurrent temporal high-grade glioma are described. Our FD and DSI tractography of the anterior commissure disclosed a new anatomical paradigm. The FD confirmed that the anterior limb (absent sometimes and variable) and the lateral/temporal extension include the rostral portion and caudal portion, respectively, of the anterior commissure fibers. The shape of the lateral/temporal extension predominantly resembles an 'H'. The DSI tractography findings corresponded to these FD results. According to the FD, the Virchow-Robin space is continuous with the subarachnoid space and very close to the anterior commissure. The two clinical cases presented severe disturbances of consciousness and behavior despite good local tumor control. Subsequent magnetic resonance images showed new lesions infiltrating the contralateral temporal lobes. FD combined with DSI provided anatomical details facilitating a better understanding of the anterior commissure. Glioma migration routes to the contralateral temporal lobe included the anterior commissure, Virchow-Robin space, and subarachnoid space and were clinically relevant.

In Vivo Elongation Patterns of the Collateral Ligaments in Healthy Knees During Functional Activities.

Improved knowledge of in vivo function of the collateral ligaments is essential for enhancing rehabilitation and guiding surgical reconstruction as well as soft-tissue balancing in total knee arthroplasty. The aim of this study was to quantify in vivo elongation patterns of the collateral ligaments throughout complete cycles of functional activities. Knee kinematics were measured using radiographic images captured with a mobile fluoroscope while healthy subjects performed level walking, downhill walking, and stair descent. The registered in vivo tibiofemoral kinematics were then used to drive subject-specific multibody knee models to track collateral ligament elongation. The elongation patterns of the medial collateral ligament varied distinctly among its bundles, ranging from lengthening of the anterior fibers to shortening of the posterior bundle with increases in the knee flexion angle. The elongation patterns of the lateral collateral ligament varied considerably among subjects. It showed an average 4% shortening with increasing flexion until 60% to 70% of the gait cycle, and then recovered during the terminal-swing phase until reaching its reference length (defined at heel strike). The observed nonuniform elongation of the medial collateral ligament bundles suggests that single-bundle reconstruction techniques may not fully restore healthy ligament function. Moreover, the observed ligament elongation patterns indicate greater varus than valgus laxity in the loaded knee. Through providing key knowledge about the in vivo elongation patterns of the collateral ligaments throughout complete cycles of functional activities, this study offers in vivo evidence for benchmarking ligament reconstruction and soft-tissue balancing in total knee arthroplasty.

BONE MARROW ASPIRATE CONCENTRATE INJECTION OF THE ACHILLES TENDON IN A COMPETITIVE DISTANCE RUNNER

Achilles tendon disorders, including tendinopathy and ruptures, are common among competitive runners. Relatively high complication rates, recurring injuries, and the need to return to sport have led to the use of regenerative medical treatment in tendon disorders in competitive athletes. Biologic therapies, including bone marrow aspirate concentrate (BMAC) injections, have been effective in restoring injured tissue in a limited number of cases. In this case, a collegiate cross country runner with Achilles tendon pain underwent years of failed, non-surgical conservative management. The patient’s MRI demonstrated moderate distal calcaneus tendinosis with high-grade partial thickness tearing of the anterior fibers of the Achilles tendon (50% tear). The patient underwent peritendinous injection of BMAC. Post-procedure MRI demonstrated minimal tendinosis of the distal and lateral margins of the Achilles tendon, and no evidence of Achilles tendon tear. The patient followed a progressive return to running program, ultimately training 40 miles per week with minimal Achilles tendon pain.

Medial collateral ligament reconstruction graft isometry is effected by femoral position more than tibial position

PurposeThe purpose of this study was to examine the length change patterns of the native medial structures of the knee and determine the effect on graft length change patterns for different tibial and femoral attachment points for previously described medial reconstructions.MethodsEight cadaveric knee specimens were prepared by removing the skin and subcutaneous fat. The sartorius fascia was divided to allow clear identification of the medial ligamentous structures. Knees were then mounted in a custom-made rig and the quadriceps muscle and the iliotibial tract were loaded, using cables and hanging weights. Threads were mounted between tibial and femoral pins positioned in the anterior, middle, and posterior parts of the attachment sites of the native superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL). Pins were also placed at the attachment sites relating to two commonly used medial reconstructions (Bosworth/Lind and LaPrade). Length changes between the tibiofemoral pin combinations were measured using a rotary encoder as the knee was flexed through an arc of 0–120°.ResultsWith knee flexion, the anterior fibres of the sMCL tightened (increased in length 7.4% ± 2.9%) whilst the posterior fibres slackened (decreased in length 8.3% ± 3.1%). All fibre regions of the POL displayed a uniform lengthening of approximately 25% between 0 and 120° knee flexion.The most isometric tibiofemoral combination was between pins placed representing the middle fibres of the sMCL (Length change = 5.4% ± 2.1% with knee flexion). The simulated sMCL reconstruction that produced the least length change was the Lind/Bosworth reconstruction with the tibial attachment at the insertion of the semitendinosus and the femoral attachment in the posterior part of the native sMCL attachment side (5.4 ± 2.2%). This appeared more isometric than using the attachment positions described for the LaPrade reconstruction (10.0 ± 4.8%).ConclusionThe complex behaviour of the native MCL could not be imitated by a single point-to-point combination and surgeons should be aware that small changes in the femoral MCL graft attachment position will significantly effect graft length change patterns. Reconstructing the sMCL with a semitendinosus autograft, left attached distally to its tibial insertion, would appear to have a minimal effect on length change compared to detaching it and using the native tibial attachment site. A POL graft must always be tensioned near extension to avoid capturing the knee or graft failure.

Abductor reconstruction with gluteus maximus transfer in revision hemiarthroplasty

Introduction: Abductor deficiency can be a debilitating problem following hip arthroplasty surgery and causes severe pain, limp and instability. Description of Technique: The authors had experienced abductor deficiency secondary to hemiarthroplasy following which a revision hemiarthroplasty was done and abductor reconstruction was performed using the anterior fibres of gluteus maximus. This flap served as a substitute for gluteus medius and minimus. Ultimately, both limp and pain showed prominent reduction. Keywords: Abductor reconstruction with gluteus maximus, Revision hemiarthroplasty.

Length change pattern of the medial structures of the knee and related reconstructions

Introduction:Aim of the study was to investigate the length changes of the medial structures and related reconstructions. It was assumed that the three fibre sections (anterior/middle/posterior) of the superficial medial collateral ligament (sMCL) have different length change patterns, which cannot be imitated by current reconstructions.Hypotheses:The three fibre sections (anterior/middle/posterior) of the superficial medial collateral ligament (sMCL) cannot be imitated by current reconstructions.Methods:Measurements were made on eight cadaveric knees. The knee joints were clamped in a custom-made open chain extension structure. For this purpose, the portions of the quadriceps and the iliotibial tract were aligned according to their fibre direction and statically loaded using hanging weights. The respective tibial and femoral insertion points of the sMCL anterior/middle/posterior fibres were marked by small pins. Similarly, pins were inserted at the tibial and femoral attachment sites of the posterior oblique ligament (POL). In order to imitate the Lind reconstruction, a pin was additionally inserted on the tibial semitendinosus insertion site. Pin combinations accounting for the anterior/middle/posterior sMCL, the POL, and the Lind reconstruction were connected using a high resistant suture. Then the length change patterns were measured using a rotary encoder from 0-120° knee flexion. Statistical analysis was performed using 2-way repeated-measures ANOVA and a post-hoc Bonferroni correction (p <0.05).Results:The anterior and posterior fibres of the sMCL showed a reciprocal behaviour (p< 0.001). The anterior fibres showed a length reduction (2%) up to a flexion of 20°, followed by an elongation of 5% at 120° flexion, which means that the anterior fibres are tight in knee flexion. Conversely, the posterior fibres of the MCL showed an initial length reduction of 4% at 20° flexion. This was followed by an isometric range (20° - 80°) and a further length reduction of 8% in deep flexion (120°). Thus, the posterior fibres of the MCL were tight in extension.The three parts of the POL showed a constant reduction of 25% between 0° and 120°. The Lind reconstruction with the tibial pin at the semitendinosus insertion site showed similar length changes compared to the sMCL (n.s.). Furthermore, the Lind reconstruction was dependent on the femoral placement of the pins (p <.001). The tibial placement had no significant influence.Conclusion:The anterior portion of the sMCL was tight in flexion, whereas the posterior portion was tight in extension. This reciprocal behavior could not be imitated by a single point to point reconstruction. When surgically applying these reconstructions, special attention should be paid to the femoral insertion.

Modified Anterior Superior Oblique Tuck: A Case Series

ABSTRACT Purpose Selection of the ideal procedure to correct symptomatic excyclotropia depends on several factors including the degree of torsion and associated vertical, horizontal and pattern deviation. Selective tuck of the anterior temporal torsional fibers of the superior oblique (SO) tendon is an alternative procedure to the classical Harada-Ito. The purpose of this study is to report its stability and results. Methods Retrospective review of all consecutive patients with symptomatic excyclotorsion of at least 5º (degrees) treated by selectively splitting and tucking the anterior temporal fibers of the SO tendon. Torsion in primary position was measured using the double Maddox Rods. Patients with additional symptomatic vertical or horizontal diplopia underwent simultaneous surgery on other extraocular muscles. Results Five patients were studied. Mean age was 60 ± 8 years (47–67). Mean postoperative follow-up was 10 ± 8 months (3–21). The mean preoperative torsion of 11º±4º (7º-15º) significantly decreased to 3º±2º (p = .03) at the first postoperative visit (16 ± 9 days) and 3 ± 2º during the last visit (P = .03). The procedure corrected 1.4º±0.9º per mm of tuck. Postoperatively no patient complained of torsion. No undesirable vertical or horizontal deviations were noted. Conclusion This technique is a simple alternative to manage symptomatic excyclotorsion, with significant and stable relief of moderate amounts of torsion and without inducing unexpected vertical or horizontal deviation.

Differences in Electromygraphic Activity of the Middle and the Lower Serratus Anterior Fibers During Open and Closed Kinematics Exercises.

Ratanapinunchai, J and Madeeyoh, I. Differences in electromygraphic activity of the middle and the lower serratus anterior fibers during open and closed kinematics exercises. J Strength Cond Res 36(7): 1788-1792, 2022-This paper seeks to determine differences in muscle activation between the middle (MSA) and the lower serratus anterior (LSA) fibers during 3 exercises. Fifteen healthy men were recruited for the study. Bench push-up plus (BPUP), unstable BPUP (UPUP), and resisted shoulder flexion (RSF) with 10 repetitions at maximum weight were tested. The normalized electromyographic (EMG) activity of the MSA and the LSA was recorded during isometric scapular protraction for BPUP and UPUP or at 150° shoulder flexion for RSF. Normalization was calculated using maximum voluntary isometric scapular protraction activity (%EMG). The results showed that the ratio of %EMG of MSA:LSA was higher than one in BPUP (1.41 ± 0.36) and UPUP (1.81 ± 0.47), but less than one (0.86 ± 0.27) in RSF. These ratios were statistically significantly different (p < 0.05). The activity of MSA and LSA in RSF was significantly (p < 0.002) higher than that of BPUP and UPUP (%EMG of the MSA = 80.53 ± 26.07, 64.75 ± 23.19 and 55.62 ± 25.56 for the RSF, BPUP, and UPUP, respectively; %EMG of LSA = 95.54 ± 24.15, 50.71 ± 26.32, and 32.26 ± 16.14 for the RSF, BPUP, and UPUP, respectively). There was no difference in the %EMG of MSA and LSA between BPUP and UPUP. The MSA worked more than the LSA in the push-up plus (PUP), but the opposite was found in the RSF exercise. The study suggests different functions of the MSA and the LSA. Different exercises should be used, including a PUP for the MSA and RSF for the LSA, or a combination to emphasize both parts of the SA.