IT Band Research Articles

Knee Pain That Wasn’t in a Twin Cities Marathon Finisher

HISTORY: A 53 yo male marathon runner presented to the medical tent after finishing race complaining of R lat knee & ant distal thigh pain. His R knee “gave out” 30 m from finish line. He hopped on his L leg to finish the race (3 hr 45 min). He had completed several marathons without incident. He trained for 22 wk, but had 6 wk of self-diagnosed R “IT band pain” leading up to the race. He described his pain as starting in the hip & radiating down the thigh to his knee. He did not seek medical attention for this pain. He had no past hx of stress fx, disordered eating, or tobacco use. Takes Vit D & calcium daily & drinks milk regularly. PHYSICAL EXAM:Gait: Unable to bear weight. Inspection: (+) spasm of R quadriceps. No swelling, erythema, ecchymosis or atrophy. Palpation: Tender along groin, greater trochanter, & Gerdy’s tubercle. No effusion of knee or hip joint. Quad tendon-without noticeable defect. Knee non-tender. Active ROM: Unable to actively flex hip or elevate leg. SLR painful. Passive ROM & Strength: Hip & knee - limited by pain, able to fire quad against gravity & slide foot along bed in extension. Ligament Stability: Knee - Varus/valgus testing, ant & post drawer, & Lachman’s firm end points, R Lachman “looser” than L; inferior traction on R lower leg while in knee extension provided “instant pain relief” per patient.Leg Position: After pain relieved, R leg was externally rotated & shortened. DIFFERENTIAL DIAGNOSIS: Femur Fx (Femoral neck, head, or shaft) Quad tendon strain/rupture Patellar tendon rupture ITB rupture ACL sprain/rupture TESTS AND RESULTS: Imaging: Xray Femur: Comminuted fracture of femoral diaphysis with displacement & angulation. CT Scan Femur: Comminuted fx of femoral diaphysis centered proximal to middle-distal 1/3 junction with angulation & displacement. No underlying lytic lesion. R femoral neck synovial herniation pit described as normal variant, but also associated with femoral acetabular impingement. Labs: Testosterone: 726 ng/dl (nrl) Vit D: 38 ng/ml (nrl) FINAL/WORKING DIAGNOSIS: R Comminuted midshaft femur fracture atop a stress fx in marathon finisher TREATMENT AND OUTCOMES: ED transport by private vehicle Orthopedic surgeon determined surgery indicated Surgical procedure - locked intramedullary nail implanted Post Op: WBAT & ROM of hip & knee as tolerated DEXA scan scheduled

Hip Pain - High School Track Athlete

HISTORY: 17 year old female track and cheer athlete presents to our sports medicine clinic with lateral and anterior left hip pain with snapping which had been present for 6 months. The lateral hip pain was worse with activity and associated with snapping. Anterior hip pain was deep and present even while at rest. No numbness or tingling. No fever or chills. She recalled no mechanism of injury or prior symptoms. She had been seen 4 weeks prior, diagnosed with trochanteric bursitis for her lateral pain, and treated with oral prednisone after declining an injection. She then attended formal physical therapy for pelvic stabilization, ASTYM and eccentric strengthening for her hip abductor /flexors. Despite these efforts, she had seen little improvement. PHYSICAL EXAMINATION: Tender to palpation on left greater trochanteric bursa and on the left hip flexor tendons. Decreased hip abduction strength on left with medial collapse on single leg squat. Tight IT band on the left compared to right. Full IR/ER ROM of the hip with no pain and negative impingement tests. No snapping palpated with ROM. Normal femoral pulses. No adenopathy. DIFFERENTIAL DIAGNOSIS: 1. Greater trochanteric bursitis/Gluteus medius tendinosis 2. Iliopsoas bursitis/Hip flexor tendinosis 3. Acetabular labral tear 4. Hip impingement 5. Femoral stress fracture 6. Ovarian dermoid cyst 7. Fecalith 8. Phebolith TEST AND RESULTS: AP pelvis with cross-table lateral of left hip -No significant hip abnormality is identified. -Triangular 1.1cm pelvic calcification of undetermined exact location and etiology. 45° and 90° Dunn views of pelvis -Normal Dunn views, opaque foreign body Repeat AP pelvis - 1 month -Similar to prior imaging, 1.1cm triangular calcification CT of pelvis with and without contrast -8.8x6.2x8.3cm mixed density mass arising from right ovary consistent with ovarian dermoid cyst FINAL WORKING DIAGNOSIS: 1. Ovarian dermoid cyst 2. Left hip pain secondary to ovarian dermoid cyst versus hip flexor tendinosis versus acetabular labral tear TREATMENT AND OUTCOMES: 1. Referral to OB/GYN for surgical consultation 2. Continue home exercise program of eccentric strengthening of hip flexors and abductors 3. Possible MRA of hip if hip pain not improved with surgical removal of dermoid cyst and proceed as clinically indicated after MRA

English

Background and Objectives: The study was carried out to find out the effect of hip abductor strengthening among non-professional cyclists with iliotibial band friction syndrome. Subjects: 40 non-professional cyclists with ipsilateral ITBFS subject including male and female age between 18 to 50 with positive ober’s and nobble test were included in this study. Methods: 40 subject were selected according to the inclusion criteria and they were assessed pre and post for ROM (hip adduction, IR), hip abductor strength and pain using goniometer,sphygmomanometer and VAS .Subject were assign experimental group(group A 20 subject) who received IT band stretching,US,and hip abductor strengthening exercise and control group (group B 20 subject) who received same treatment except hip abductor strengthening. Data Analysis and Results: Based on statistical analysis using Wilcoxon test to compare the pre and post test pain in both group,Mann- whitney U- test to compare the post test pain scores of between groups ,Paired t - test to compare the pre and post ROM and strength in both groups, Unpaired t – test to compare post test ROM in between groups showed that pre post difference within group A there was significant difference for adduction ROM (p value <.0001),IR (p value <.0001),VAS(p value <.0001),and strength improve pre mean 40.80 to post mean 66.30 (p value <.0001).However in group B adduction ROM and VAS were found to be significant. In comparision in difference between groups it was found that adduction ROM,IR ROM,VAS and strength all were significant. Baseline data for outcome variable were not statistically significant. Conclusion: Based on outcome variable there was significant difference of hip abductor strengthening among non-professional cyclist with iliotibial band friction syndrome.

MRI Evaluation of the Anterolateral Ligament of the Knee In The Setting of ACL Rupture

Objectives:The anterolateral ligament (ALL) of the knee was recently described in the literature. It was hypothesized to help control internal tibial rotation and affect the pivot shift phenomenon. The purpose of this study was to identify the normal appearance of the ALL on magnetic resonance imaging (MRI) and to examine its role in stability of the knee.Methods:A retrospective chart review was performed and 50 patients from a single surgeon’s practice with full thickness anterior cruciate ligament tears over a 2 year period were selected at random. Operative reports detailing the pivot shift examination under anesthesia were documented. Preoperative MRIs were reviewed by a fellowship trained musculoskeletal radiologist. Axial, sagittal, and coronal cuts were used to identify the presence and degree of injury to the ALL (Grade 0-3). The popliteus tendon, lateral collateral ligament, biceps femoris tendon, and iliotibial band were analyzed and graded 0-3. The presence or absence of a Segond fracture was noted.Results:The ALL was identified in 100% of the anterior cruciate ligament deficient knees evaluated. In 27 knees, there was no MRI evidence of ALL injury (Grade 0). A grade 1 injury was noted in 18 knees. A grade 2 injury was noted in 2 knees. A grade 3 injury was observed in only 1 knee. This was the same knee in which the single Segond fracture among the group was noted. Eighty four percent (42/50) of knees showed a positive pivot shift on examination under anesthesia. A positive pivot shift was noted in 37 patients who had no (Grade 0) or mild (Grade 1) ALL injury. Thirteen MRIs showed evidence of injury to the posterolateral corner structures, with 92% (12/13) consisting of mild (Grade 1) injuries.Conclusion:The anterolateral ligament of the knee is readily identifiable on MRI. Its structural integrity was maintained in the overwhelming majority of knees with a complete tear of the ACL, both with and without the presence of rotatory instability on examination. We found no correlation between degree of injury to the ALL and degree of instability. The only complete rupture of the ligament was in the setting of complete rupture of the IT band, which supports its identity as an extension of the IT band. Therefore, we propose that the ALL in itself plays a minimal if any role in stability of the knee. Further biomechanical studies are needed to confirm this.

CSM 2014 Sports Physical Therapy Section Poster Presentations (Abstracts SPO1228–SPO1309, SPO6761)

CSM 2014 Sports Physical Therapy Section Poster Presentations (Abstracts SPO1228–SPO1309, SPO6761)

Relationship between Iliotibial Band Tightness and Occurance of Low Back Pain and Sciatica

Back pain is the most frequent and common problem in the society. It is also one of the most frequent presenting symptoms in clinical practice1. The incidence of low back ache (LBA) in the population is increasing rapidly. Among the new episodes of back pain, 80% leads to chronic disability and chronic back pain4. Most of the previous studies have indicated that 70% to 80% of the population has had at least one episode of LBA in their lifetime The mechanical low back pain is the pain, which varies with physical activity [e.g.- prolonged sitting, bending forward] and with time. This pain is located in the lumbosacral region, buttocks and thighs with no radiation to foot or toes. The pain increases or decreases with repeated movement 1. Sciatica refers to a neurotic type of pain along the course of the sciatic nerve. Pain extends down the posterior thigh, lower leg to the sole of the foot and along lateral aspect of the lower leg to the dorsum of the foot. A number of studies have been done to find out the association of these mechanical factors with LBA. Frank R. Ober, performed fasciotomy for patients with LBA and sciatica and found marked diminution in symptoms for majority of patients within twenty four hours following operation. However till date, hardly any studies have been done to find out the correlation of IT band tightness and the occurrence of LBA and sciatica.

Diagnostic Differences for Anterior Knee Pain between Sexes in Adolescent Basketball Players.

The purpose of this study was to determine if there is a sex difference in the prevalence of specific patellofemoral disorders that cause anterior knee pain in adolescent basketball players undergoing pre-participation screening. Biomechanical Laboratory. A total of 810 (688 female and 122 male) basketball players from a single county public school district. Prior to the start of three consecutive basketball seasons, participants were evaluated for anterior knee pain. Testing consisted of completion of the Anterior Knee Pain Scale. Those with positive findings completed an IKDC form, a standardized history and a physician-administered physical examination. Anterior knee pain was noted in 410 of 1620 knees (25.3%). 26.6% of female knees and 18.0% of male knees were affected (p<0.05). Patellofemoral dysfunction (PFD) was the most common diagnosis with an overall prevalence of 6.4% (7.3% females; 1.2% males). Less common were Sinding-Larsen-Johanssen disease (SLJ), 4.8% (5.0% females; 3.7% males), Osgood-Schlatter Disease (OSD) 2.5% (2.3% females; 4.1% males); and plica syndrome 2.3% (2.1% females; 3.3% males). The remaining diagnoses (trauma, fat pad syndrome, IT band and pes anserine bursitis) had a combined prevalence of 1.7% (1.9% females; 1.6% males). PFD was significantly more common in females (p<0.05). Anterior knee pain was more common in adolescent female basketball players than in adolescent male basketball players. Descriptive Laboratory Study. Level 1.

Surgical Technique: Tscherne-Johnson Extensile Approach for Tibial Plateau Fractures

BackgroundThe standard approach to lateral tibial plateau fractures involves elevation of the iliotibial band (IT) and anterior tibialis origin in continuity from Gerdy’s tubercle and metaphyseal flare. We describe an alternative approach to increase lateral plateau joint exposure and maintain iliotibial band insertion to Gerdy’s tubercle.Description of TechniqueThe approach entails a partial tenotomy of the anterior half of the IT band leaving the posterior IT band insertion attached to Gerdy’s tubercle. Fracture lines around Gerdy’s tubercle are completed or the tubercle was osteotomized and externally rotated and the joint overdistracted, allowing direct visualization of the joint depression. Joint elevation, grafting, and internal fixation are performed through this window.MethodsWe retrospectively reviewed 76 patients (two groups), Schatzker Types I to II and IV to VI fractures (66 patients), between 1989 and 2005, and 10 patients, with 10 bicondylar posterior plateau fractures, from 2002 to 2010. All patients were followed a minimum of 12 months (average, 3.9 years; range, 12 months to 10 years). Ten patients, with posterior plateau fractures, received anterolateral plateau intraarticular osteotomy for exposure of centroposterior and posterolateral articular depression.ResultsAverage knee ROM was 2° of flexion (range, −3° to 5°) to greater than 120° of flexion (range, 100°–145°). In 66 patients, average articular depression improved from 7.4 mm to 1 mm (range, 0–5 mm) and, in 10 posterior fractures, from 18 mm to 1 mm (range, 0–4.5 mm). Infection occurred in one of the 76 patients; acute débridement and intravenous antibiotics resulted in control of the infection.ConclusionsThis approach reliably increases direct visualization of the lateral plateau articular fractures and maintains IT band insertion. Articular osteotomy of the anterolateral plateau provides access to extensive posterior plateau fractures.Level of EvidenceLevel IV, retrospective study. See Guidelines for Authors for a complete description of levels of evidence.

What does it take to have a high-grade pivot shift?

The pivot shift is the most specific clinical test to assess pathological knee joint rotatory laxity following ACL injury. This article attempts to describe the anatomic structures responsible for creating a high-grade pivot shift and their potential role in customizing ACL reconstruction. A review of the literature demonstrates that disruption of the secondary stabilizers of anterior translation of the lateral compartment including the lateral meniscus, anterolateral capsule, and IT band contributes to a high-grade pivot shift in the ACL-deficient knee. The morphology of the lateral tibial plateau, including increased posteroinferior tibial slope and small size, can also contribute to high-grade pivot shift. Factors that may decrease the grade of the pivot shift include medial compartment injury, MCL injury, patient guarding, and osteoarthritis. In conclusion, a high-grade pivot shift in the ACL-deficient knee is often associated with incompetence of the lateral soft tissue envelope. Rotatory laxity as assessed by the pivot shift may also be falsely underestimated by concomitant injuries. IV.

Proximal iliotibial band syndrome: what is it and where is it?

To describe the clinical and MR imaging features of a unique strain at the iliac tubercle enthesis. While this strain appeared to correspond to the iliotibial band (IT band) enthesis, the literature regarding the IT band origin was discrepant. As such, our second goal was to prove that the IT band originated at the iliac tubercle, through cadaveric dissection. Three musculoskeletal radiologists prospectively reviewed 67 consecutive bony pelvis MRI studies from October 2006 through September 2008 using either 3, 1.5, or 0.3T units. Seven cases demonstrating strain at the iliac tubercle enthesis were identified and reviewed by consensus. History and patient demographics were reviewed. Cadaveric dissection was performed to delineate the anatomy of the proximal IT band. Seven out of 67 individuals, all women, were identified with strain at the level of the iliac tubercle (prevalence 10%). Four of seven were athletes, three were overweight. Patients presented with pain and tenderness at the iliac tubercle. Anatomic dissection confirmed that iliotibial band originates along the margin of the iliac crest with dominant fibers condensing on the iliac tubercle. Proximal IT band strain represents a unique injury that should be considered in patients who are female athletes or older overweight women who present with pain and tenderness at the iliac tubercle. Imaging of this entity must include the iliac tubercle, which is often excluded in standard hip MRI.

Examining Biomechanical and Anthropometrical Factors as Contributors to Iliotibial Band Friction Syndrome

Examining Biomechanical and Anthropometrical Factors as Contributors to Iliotibial Band Friction SyndromeThis study was conducted in an attempt to determine if the biomechanical parameters thought to predict iliotibial band injury could accurately differentiate between iliotibial band (IT band) injured and healthy runners. 20 injured and 20 healthy runners were tested. Injured subjects were randomly assigned into groups of ten (INJ-1 or INJ-2). Ten healthy runners acted as controls (CON) and ten healthy (EXP) subjects trained for 1 week with a 1.27 cm felt heal pad in the shoe of their longer leg. All subjects completed a runner's questionnaire, and 13 lower extremity anatomical measurements, four clinical lower extremity assessments, and 2D kinematics from the sagittal and frontal planes during treadmill running were recorded. Comparison of kinematic values between INJ-1 vs. CON and INJ-2 vs. EXP indicated the INJ-1 group had a greater knee flexion angle than the CON group. No other direct comparisons revealed statistically significant differences between groups, nor did a discriminant function based on nine anatomical measurements or analysis of the running questionnaire responses. It was not possible to clearly distinguish between the healthy and injured runners of this study based on the biomechanical factors most commonly thought to predispose individuals to iliotibial band injury.

AN IMPAIRMENT-BASED INTERVENTION FOR A PATIENT WITH NON-SPECIFIC BILATERAL HIP PAIN: CLINICAL AND BIOMECHANICAL OUTCOMES

Study design: Case study. Background: To date, there is little research that has examined the association of impairments at the hip with cumulative trauma syndromes of the hip. The purposes of this case report are to: (1) describe clinical outcomes for a patient with non-specific bilateral musculoskeletal hip pain associated with recreational walking, (2) explore the relationship between this patient's impairments and her cumulative trauma syndrome at the hip, and (3) integrate biomechanical analysis with this patient's clinical diagnosis. Case description: The patient was a 28-year-old female research assistant who reported anterior bilateral hip pain during recreational walking. After examination, the physical therapist diagnosed primary impairments of hip pain, limited hip flexion range of motion (ROM), and weakness of hip musculature, resulting in her ambulation limitations. Intervention consisted of a home exercise program (HEP) designed to strengthen the iliopsoas, gluteus maximus, and gluteus medius (specifically, the posterior portion), increase extensibility of the IT Band and medial hamstrings, and promote posterior glide of the proximal femur. The patient's HEP was the only intervention she received. There were follow-up telephone conversations, but no clinical re-examination for ten weeks. The patient performed the HEP a total of 41 days over the ten week period. Biomechanical gait analysis was performed pre- and post-intervention. Outcomes: Following intervention, the patient was pain-free during recreational walking, and passive hip flexion ROM and manual muscle testing (MMT) grades of hip musculature improved. Global score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) improved ten points. Motion analysis, force plate analysis, and electromyography (EMG) showed that maximum hip extension decreased, maximum hip flexion increased, maximum ground reaction force increased, activation of the gluteus maximus increased, while activation of the gluteus medius and tensor fascia latae (TFL) decreased following the intervention. Discussion: This patient's changes in muscle activity following a HEP appear largely consistent with improved symptoms based on theoretical descriptions of a common muscle imbalance (shortened and overactive TFL and weakness of the gluteus maximus and posterior portion of the gluteus medius), thought to contribute to increased femoral medial rotation.

Excited State Intervalence Transfer in a Rigid Polymeric Film

The ligand-bridged complex cis,cis-[(bpy)2ClRu(pz)RuCl(bpy)2]2+ as the PF6- salt, (1)(PF6)2, is stabilized toward photochemical ligand loss in poly(methyl methacrylate) (PMMA). Stabilization allows measurement of metal-to-ligand charge transfer (MLCT) photophysical properties--emission and transient absorption. This includes appearance of an intervalence transfer absorption band in the near IR spectrum of the photochemically prepared, mixed valence form, [(bpy)2ClRuIII(pz(-*))RuIICl(bpy)2](PF6)2* (1*(PF6)2). Comparison of its IT band properties with those of ground state cis,cis-(bpy)2ClRuIII(pz)RuIICl(bpy)2]3+ in CD3CN allows a comparison to be made between pz and pz(-*) as bridging ligands. A model based on differences between rigid and fluid media provides an explanation for decreased IT band energies and widths in PMMA and provides important insight into electron transfer in rigid media.

Knee Pain - Acute on Chronic - Football Player

HISTORY A 14 year-old male presented to sports clinic with a complaint of left knee pain for five days. The patient is an offensive guard for his high school freshman football team. He stated that his injury occurred when he stepped on another player's foot while walking backwards which caused him to hyperextend his knee. At that point, he was unable to continue playing secondary to pain. He later felt the pain localized laterally across the knee. He also experienced swelling the following day, along with a sensation of locking or clicking. He had increased pain with stair climbing. The patient did report a previous hyperextension injury of the left knee six months prior to presenting to clinic with residual pain and swelling. These symptoms resolved and he had played without any problems. PMH/PSH: Negative Medications: Ibuprofen prn pain. No supplements, herbs, vitamins or prescription drugs Allergies: NKDA PHYSICAL EXAMINATION The patient was in no acute distress, walking with a nonantalgic gait. Vitals: Temp= 98.7 Pulse = 70 RR = 16 BP = 130/70 Weight = 260 Height =6′2″ Examination of lower extremities: Active ROM full at the hip and ankle bilaterally. The left knee was lacking full extension while prone with a heel height difference of 4cm. A mild effusion was present at the knee joint. The Patella was non-tender. Negative patellar apprehension and grind tests. Normal patellar tracking and good VMO strength. Mild anterolateral joint line tenderness. No tenderness at fibular head or IT Band. McMurray's, Anterior and Posterior drawer and Lachman's tests were negative. Negative valgus and varus laxity at 0 and 30 degrees. Positive pain at lateral joint line with varus stress. Negative external rotation recurvatum test. Negative Ober's. Positive difficulty with squatting. Differential Diagnosis Meniscal Injury Lateral Collateral Ligament Injury Posterolateral Corner Injury Osteochondral Defect (OCD) Patellar Subluxation TESTS AND RESULTS Xrays Left knee plain films read by Radiology as normal. However, in clinic reviewed and found to have a cortical disruption with OCD in the anterior lateral aspect of femoral condyle MRI left Knee Large OCD involving the anterior aspect of the lateral femoral condyle with a loose body noted anterior to the insertion site of the ACL most likely arising from the site of the OCD. ACL, PCL, LCL, MCL and menisci intact. FINAL WORKING DIAGNOSIS OCD of lateral femoral condyle with loose body TREATMENT AND OUTCOMES Nonweightbearing and orthopedic referral Scheduled arthroscopy with loose body removal. Possible microfracture, possible cartilage biopsy, possible internal fixation.

Methodological concerns using intra-cortical pins to measure tibiofemoral kinematics.

The complexity of human tibiofemoral joint motion is now better understood with the advancement of new methodologies to measure tibiofemoral kinematics in vivo. Marker clusters anchored to stainless steel bone pins inserted directly into the femur and tibia provide the most sensitive and accurate means for directly measuring skeletal tibiofemoral joint motion. Despite its invasiveness, this technique has been successful, although complications have been reported with the femoral pin and its insertion site. The purpose of this technical report is twofold: to review the difficulties with the femoral pin and its insertion site from a historical perspective, and to identify the load force required from biological tissue to permanently deform the pin. In addition, proposals in the advancement of this method are discussed in the context of reducing impingement with the femoral pin and the Iliotibial band. Because stainless steel exhibits plastic behaviour with no sharp yield point, Apex self-drilling/self-tapping bone pins underwent incremental loading on an Instron materials testing machine. Loads were transmitted perpendicular to the pin with the threads partially exposed and fully secured in vice. Since the accuracy of our combined stereophotogrammetry and Optoelectric motion analysis was less than 0.4 mm, it was decided that plastic deformation occurred after deflections of 0.4 mm. With exposed threads, deflections larger than 0.4 mm were observed at 150 N and 100 N when loads were applied at 15 mm and 20 mm from the vice (representative of where the tissue came in contact with the pin). Loads greater than 200 N produced deflections less than 0.2 mm when threads were fully inserted. The 90 Hz resonant frequency for the marker cluster-bone pin complex is beyond the spectrum of human movement and can be lowpass filtered. To reduce impingement and pin bending, one solution may be to implant pins with a shorter threaded section. By completely penetrating the bone, only the smooth surface of the pin is exposed which is more resistant to bending. Otherwise pins with larger diameters and longer longitudinal incisions about the femoral insertion site are an alternative. Lengthening the longitudinal incisions about the insertion site, and correctly aligning and inserting the femoral pin between the Iliotibial band and quadriceps tendon may diminish impingement. Performing dynamic open chain flexion and extension movements while on the operating table may aid in aligning the pin at the incision site. This may stretch the IT band and quadriceps tendon and may guide the femoral pin into a more optimal position prior to it being inserted into the cortex of the bone.

Synthesis and redox property of the binuclear Pt(II) complexes bridged by thieno[3,2- b]thiophenes

The binuclear Pt(II) complexes bridged by thieno[3,2- b]thiophenes were prepared and their redox behavior was measured by cyclic voltammetry. The complexes showed two one-electron quasi-reversible waves and their first redox potentials are comparable with that of ferrocene. The oxidation potentials of the complexes and the related complexes are explained by the result of the MO calculation. The one-electron oxidation of some complexes gave stable oxidized complexes which showed no IT band in the near infrared region. The electronic and EPR spectra suggest that an unpaired electron is localized on the Pt atom.

Primary total knee arthroplasty in the valgus knee: Creating a balanced soft tissue envelope

Lateral tissue releases in valgus total knee arthroplasty frequently produce asymmetric flexion-extension gaps and ligamentous instability. This study compared 2 lateral-release sequences and quantified the effects of sequential lateral capsular ligamentous structure release. One knee from 7 paired specimens was released according to a 4-step sequence: posterior cruciate ligament (PCL), ibiotibial tract (IT band), popliteus tendon/lateral collateral ligament (PT/LCL), and biceps femoris tendon. The contralateral knees were released according to a 5-step sequence: PCL, posterolateral capsule, IT band, PT, and LCL. After each release step, flexion and extension gaps were measured and recorded for the medial and lateral aspects. The 5-step sequence produced more symmetric flexion-extension gaps, whereas the absolute magnitudes of correction were lower than with the 4-step sequence. LCL sacrifice in both sequences produced marked lateral flexion-extension gap asymmetry.

EXAMINATION OF BIOMECHANICAL AND ANATOMICAL FACTORS AS CONTRIBUTORS TO ILIOTIBIAL BAND FRICTION SYNDROME

This study was conducted in an attempt to determine if the biomechanical and anatomical factors associated with iliotibial band (IT band) injury are quantitatively different between IT band injured and healthy runners. Positive correlation between the measurements and injury would provide information that could be used to develop better prevention and treatment programs for runners susceptible to this common injury. Forty runners, 20 injured and 20 healthy, participated in the study and were divided into 4 groups in order to examine the effects of leg length discrepancy. The 20 injured participants were randomly assigned into one of two groups of 10 (INJ-1 or INJ-2). INJ-1 was compared to 10 healthy control (CON) individuals. INJ-2 was compared to a group of 10 healthy runners (EXP) who trained for one week with a 1.27 cm felt heel pad in the shoe of their longer leg. Data were collected from all participants using a runner's questionnaire, 13 lower extremity anatomical measurements, 4 clinical lower extremity assessments, and 2D kinematics captured from the sagittal and frontal planes during treadmill running. Kinematic results indicated the INJ-1 group had a greater knee flexion angle than the CON group (p < 0.05). No other direct comparisons revealed statistically significant differences between groups, nor did a discriminant function analysis based on 9 anatomical measurements. Analysis of the running questionnaire responses did not indicate significant difference in training regimen between the injured or healthy participants. In summary, it was not possible to clearly identify differences in the biomechanical, anatomical, and training regimen factors most commonly thought to predispose individuals to iliotibial band injury. We believe that future research should focus on pelvic motion, pelvic muscle activity, leg strength, and/or flexibility variables.

Temperature Dependence of the Outer-Sphere Reorganization Energy

The temperature dependence of the intervalence charge transfer transition (IT) has been studied for a mixed-valence dinuclear iron complex. The two “halves” of this complex consist of trisbipyridineiron moieties that are triply linked with saturated alkyl chains. Because the complex is symmetric, the energy of the IT band is a direct measure of the reorganization energy for electron transfer between the two irons. Moreover, for the specific complex under investigation here, the inner-sphere reorganization energy is essentially zero because of an exact cancellation of sigma- and pi-bonding changes upon changing the oxidation state of each iron. As a consequence, the energy of the IT transition is a direct measure of the outer-sphere (solvent) reorganization energy. The energy of the IT band has been investigated over the temperature range −28 °C to 30 °C. The derivative of the outer-sphere reorganization energy with respect to temperature found from this study was −3.2 ± 0.4 cm-1K-1. Theoretical calculations based on the Marcus two spheres in a dielectric continuum model and a molecular based model developed by Matyushov were also carried out for comparison with the experimental results. The continuum model predicts a positive slope for the derivative while the Matyushov model gives a negative slope that differs from that of the experimental data by a factor of ∼2 in magnitude.

Spectroelectrochemical Analysis of the Intervalence Band in Mixed-Valence Di- and Tetranuclear Ru Complexes by the Flow-Through Method.

New convenient spectral analysis of IT band for partially oxidized species was developed by using the combination of digital simulation analysis of a reversible CV curve and an electrochemical titration with flow-through electrolysis. This method can be applicable not only for dinuclear Ru complexes but also dendritic Ru tetranuclear complexes.