Browsing by Author "Wood, Addison"
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Item CHANGE IN FORCE BETWEEN ILIOTIBIAL BAND CUT AND GLUTEUS MAXIMUS TENDON CUT(2014-03) Taylor, Victor W. II; Reeves, Rustin E.; Belmares, Ricardo; Guttmann, Geoffrey; Wood, Addison; Crofford, TheodoreIntroduction: Greater Trochanteric Pain Syndrome (GTPS) is a hip pain due to repeated trauma to bursa on the greater trochanter. Surgical procedure cut the iliotibial band (IT band) in order to relieve the pressure around the greater trochanter. However, the IT band may not be the primary cause of GTPS. It is hypothesized the tendon of the gluteus maximus (gmax) tendon is the primary cause of GTPS. Materials: Force sensor test on the greater trochanter was performed on fresh cadavers. Cadavers were stabilized by the hip on a gurney. The skin on the top half of the thigh is reflected and cleans to expose the iliotibial band (IT band). Incision is made between the IT band and tensor fascia lata, and a force sensor from Tekscan was placed on the greater trochanter. Three measurements were done: Normal, IT cut, and gmax cut. Measurements will be made from 0o to 20o flexion and extension in increments of 10o three times, each at a fixed 0o, 10o, and 15o adduction. SPSS was used for statistical calculation. Summary: 6 hips (3 cadavers) were observed. There were no significance between normal and IT cut, as well as, between the normal and gmax cut. There were significant difference between gmax and IT cut at 0o adduction (p=.03) and 0o adduction, 10o flexion (p=.01). Conclusion: This study will help to develop new treatment approach to GTPS. More data will be collected in the future.Item Current Practices and Outcomes of Patella Fracture Fixation(2022) Quiring, Mark; Wood, AddisonPurpose Patella fractures account for approximately 1% of all fractures. Standard treatment includes nonoperative management, screw fixation, anterior tension band wiring, partial patellectomy, and plate osteosynthesis. The choice of surgical treatment is dependent on a multitude of factors, including fracture type, degree of displacement, age and expected activity, and more. Treatment of patella fractures with hardware can result in undesirable outcomes, including residual knee pain, stiffness, re-displacement or re-injury, and even hardware failure. Anterior plating of patellar fractures is a newer, promising treatment modality, reserved primarily for multifragmentation and severe displacement. This review aims to provide insight into outcomes and best practices regarding currently utilized surgical techniques for patella fractures. Methods A systematic search for articles was conducted in the PubMed database. Article types included were prospective cohort studies, retrospective reviews, and biomechanical studies, all from peer-reviewed journals. Studies conducted within the past decade (2012-2022) that analyzed fixation of various patella fracture patterns were included. Treatments of focus included standard screw fixation, tension band wiring, tension band wiring with augmentation, and various plating techniques. Fracture patterns ranged from simple transverse to complex comminuted patella fractures. Results Twenty-three studies (11 biomechanical, 8 prospective, and 4 retrospective) were included in the review, investigating a combined 394 individual patella fractures. The transverse patellar fracture was the most common fracture pattern treated and analyzed (10 articles) included in the review. Common outcomes analyzed included knee range of motion, activities of daily living, knee pain, and various standardized knee and patella scoring systems, such as the Modified Cincinnati knee rating system or the Kujala score. Conclusions Tension band wiring continues to remain a safe and proven technique for various fracture types of the patella. Plating constructs, as a newer modality, show promising results when compared to other standard methods in patella fracture fixation, including superior clinical outcomes, lower non-union rates, and fewer complications. Limitations of some plating techniques include lack of long-term data, especially the newer models, and increased associated costs. Biomechanical comparison between various anterior plates is limited and warrants further investigation.Item Diagnostic Validation of Dynamic Ultrasound Evaluation of Supination-External Rotation Ankle Injuries(2018-03-14) Fisher, Cara; Johnson, Katelyn; Reeves, Rustin; Wood, Addison; Rabbani, TebyanAbstract Purpose: Definitive diagnosis of syndesmosis injuries can be made with plain film radiographs if the injury is severe enough, but often is missed when severity or image quality is low. Ultrasound diagnosis may circumvent many of these disadvantages by being inexpensive, efficient, and able to detect subtle injuries without radiation exposure. This study evaluates the ability of ultrasound to detect subtle SER ankle syndesmosis injuries with a dynamic external rotational stress test. Methods: Nine male fresh frozen specimens were secured to an ankle rig and stress tested to 10 Nm of external rotational torque with ultrasound monitoring at the tibiofibular clear space. The ankles were subjected to syndesmosis ligament sectioning and repeat stress measurements of the tibiofibular clear space at peak torque. Ankle States Examined: 1. Intact State 2. 75% of AITFL Cut 3. 100% of AITFL Cut 4. Fibula Fx - Cut 8 cm proximal 5. 75% PITFL Cut 6. 100% PITFL Cut Results: Dynamic external rotation stress evaluation using ultrasound was able to detect a significant difference between the uninjured ankle tibiofibular clear space of 4.5 mm and the injured ankle with 100% of anterior inferior tibiofibular ligament cut 6.0 mm (P=.017). Additionally, this method was able to detect significant differences between the uninjured ankle and the injured states. Conclusion: Dynamic external rotational stress evaluation using ultrasound was able to detect stage 1 Lauge-Hansen SER injuries with statistical significance and corroborates criteria for diagnosing a syndesmosis injury at ≥ 6.0 mm of tibiofibular clear space widening.Item EFFECT OF TIBIAL SLOPE ON FLEXION AND FEMORAL ROLLBACK IN TOTAL KNEE ARTHROPLASTY: A CADAVERIC STUDY(2014-03) Chambers, Andrew W.; Wood, Addison; Kosmopoulos, Victor; Sanchez, Hugo; Wagner, RussellPurpose (a): Reduced posterior tibial slope (PTS) and posterior tibiofemoral translation (PTFT) in posterior cruciate retaining (PCR) total knee arthroplasty (TKA) has been shown to result in suboptimal postoperative knee flexion due to the occurrence of tibiofemoral impingement. Although reduced PTS and PTFT have been shown independently to negatively affect total knee flexion following TKA, there has never been a study to our knowledge that has shown the effect of PTS on PTFT. We evaluated the relationship between PTS, PTFT, and total knee flexion in a cadaveric model after TKA. Methods (b): We obtained nine transfemoral fresh frozen cadaver specimens and preformed a balanced PCR TKA. The pre-operative and post-operative PTS were precisely measured with c arm fluoroscopy and the post-operative PTS was changed in 1 degree increments using custom shims for the TKA trial components. We successively measured the total flexion using a motion tracking system in response to a 25 lb force applied to the hamstrings at 1 degree increments of posterior tibial slope (1-10 degrees). Relative PTFT was measured at maximal flexion with C-arm fluoroscopy. Results (c): We used Tukey ANOVA test to determine significant changes in flexion and PTFT as a function of PTS. We found that there was an average increase in flexion of 2.3 o per degree increase of PTS from 1o (1 degree) to 5 o (p. Conclusions (d): Small increases in PTS in the range of 1o to 5o appear to significantly increase knee flexion and PTFT. As the PTS is further increased above 5 o, these findings suggest that flexion and PTFT do not continue to increase significantly. This is the first study to find a direct relationship between PTS and PTFT. These findings may be explained by changes in PCL tension with different PTS. As the flexion gap is loosened above a threshold (5 o) with increased PTS, the relatively lax PCL likely fails to initiate PTFT and subsequent total knee flexion is subsequently decreased due to posterior tibiofemoral soft tissue impingement. Additionally, we did not observe a correlation between native PTS and optimal degree of post-operative PTS. Although these results suggest that increasing PTS above 5o does not improve flexion or PTFT, clinical judgment and proper flexion gap balancing remain paramount in maximizing post-operative knee flexion. In vivo studies will be necessary to further substantiate these conclusions.Item Kinematic Analysis of Sagittal Plane Stability of Delta Frame External Fixation(2018-03-14) Beck, Cameron; Tran, Apollo; Hoy, Austin; Barcak, Eric; Wood, AddisonPurpose: External fixation with a delta frame construct is the most common construct used for temporizing patient distal tibia and ankle injuries. While these constructs may be the most common there are numerous variations that are often performed based on surgeon preference. The inclusion or exclusion of a posterior slab or 1st metatarsal pin to the construct is variable amongst surgeons and have little data to support their use aside from anecdotal evidence. Methods: 10 Fresh Frozen Cadavers were secured to a custom-made rig that held the tibia rigid and allowed the application of a standard delta frame external fixator. The specimens had a 2 cm segment of bone resected near the ankle plafond to simulate a highly unstable distal tibia or pilon fracture. The ankle was then loaded with a 10 lb weight from the great toe and 3D kinematics were recorded using an electromagnetic tracking system with 6 degrees of freedom. The 4 construct comparisons were: 1. Delta frame 2. Delta frame with 1st metatarsal pin 3. Delta frame with posterior slab 4. Delta frame with 1st metatarsal pin and posterior slab Results: The delta frame construct without any additions was less stable than all other constructs with statistical significance in the sagittal plane with regards to flexion/extension rotation. The most stable construct was a delta frame with 1st metatarsal pin and posterior slab. The most cost-effective measure to add sagittal plane stability was the addition of the posterior slab splint. Conclusion: Delta frame stability in the sagittal plane can be cost effectively augmented by the addition of a posterior slab. The addition of both a posterior slab or 1st metatarsal pin were able to significantly add stability to the base construct and the combination of the 2 were able to achieve highest stability.Item Mechanism of Supination External Rotation Short Oblique Ankle Fractures Revisited: A Cadaveric Study(2016-03-23) Wood, Addison; Fisher, Cara; Nana, Arvind; Payne, Joshua; Le, DavidPURPOSE: The Lauge-Hansen classification system for ankle fractures has been the most commonly used system because it explained mechanism of injury of several common fracture patterns. However, there are limitations to the original Lauge-Hansen experiments and we have chosen to focus our central objective of this study on the biomechanical mechanisms behind stage 1 & 2 supination-external rotation (SER) ankle fractures in a cadaveric model. METHODS: 5 Fresh frozen cadaveric specimens were mounted into a custom made ankle rig with the tibia held rigid using half pins while allowing free movement of the fibula. The foot was secured to a wheel with a torque sensor attached to record examiner external rotational stress application. An electromagnetic tracking system was used to track the motion of the specimen with 6 degrees of freedom at each segment. A control arm was used to hold the foot in dorsiflexion while all other rotations were held in neutral. An ultrasound probe was used to monitor tibiofibular space as the examiner applied a controlled 100N maximal external rotational torque. Specimens were first tested with all ligaments intact prior to incremental resection of the anterior inferior tibiofibular ligament (AITFL) with repeat stress examination after each change. RESULTS: All specimens withstood the normal state testing of up to 100N of external rotational force without any injury. However, 4 out of 5 specimens received short oblique fracture patterns to the distal fibula after partial (75%) or full AITFL resection. Comparison of pre and post radiographs, visual observation via dissection, and live ultrasound video confirmed these results. 3D kinematics were recorded and analyzed as well to determine bone movement and fracture timing and compared to ultrasound video of the tibiofibular space. CONCLUSION: Prior studies have used unmeasured forces, non-physiological ligament strain rates, and poor alignment techniques. We sought to exclude the ligament strain rate and other design issues from our study by performing incremental resection of the AITFL as a synthetic mechanism for stage 1 SER ankle injuries and focusing on the reproducibility of the stage 2 fibula fracture in an SER injury. Our study demonstrated: 1. A 100N external rotational force did not result in an AITFL injury 2. Partial sectioning of the AITFL alongside a 100N external rotational force led to a reproducible oblique distal fibula fracture in a cadaveric ankle model.Item Muscular Architecture of the Posterior Knee and the Basic Science Implications(2016-03-23) Wood, Addison; Wagner, Russell; Reeves, Rustin; Smith, MorganIntroduction: Musculoskeletal modelling plays an integral role in estimating clinically relevant muscle and joint contact forces which rely upon cadaveric experimentation. The muscular architecture of the posterior knee is often overlooked; yet can play an important role in knee mechanics and balancing. In this sense, the contribution of the popliteus muscle to a well-functioning total knee arthroplasty is often debated in the literature and requires further clarification. Furthermore, prior literature involved smaller sample sizes and did not look for differences in muscle architecture between males and females. Methods: 12 embalmed cadaver specimens were dissected to reveal the origin and insertion of the gastrocnemius, semimembranosus, and popliteus muscles. The orientation of these muscles and the breadth of the insertion of the popliteus muscle were recorded in relation to the long axis of the tibia using a goniometer. Muscle volume was assessed via water displacement can and graduated cylinder. Muscle fiber length and pennation angle were determined under a dissecting scope using a ruler and goniometer. Fiber length was determined via dissection and measurement from 3 separate areas and averaged for each muscle. Using these data, physiological cross sectional area (PCSA) was calculated by multiplying each muscle’s volume by the cos of the pennation angle and then dividing by it’s fiber length. Results were initially analyzed using descriptive statistics. Comparison between groups was performed via ANOVA with a post hoc Tukey test for multiple comparisons. Results: Mean muscle volumes for females: popliteus 12.6 ml, gastrocnemius 108.1 ml, and semimembranosus 81.9 ml (n=7). Mean muscle volumes for males: popliteus 20.5 ml, gastrocnemius 195.6 ml, and semimembranosus 174.3 ml (n=5). Significant differences between males and females were found in all three volumes (p=.001, p=.002, and p=.010 respectively). Significant differences between males and females were also found in PCSA for the popliteus and semimembranosus muscles (p=.008, p=.003 respectively). There were no significant differences found between males and females in fiber length, overall muscle length (excludes tendon), or orientation (Table 1,2,3). The mean orientations of the popliteus, medial gastrocnemius, and lateral gastrocnemius with respect to the long axis of the tibia were 145.3 degrees, 163.8 degrees, and 162.4 degrees respectively. The tibial attachment site of the popliteus muscle spanned between 38.3 degrees and 25.5 degrees in relation to the long axis of the tibia. Several data points were unable to be adequately collected due to incidents occurring during dissection (represented by the letter x in the tables). Results were compared to prior literature when possible and were found to be similar. Discussion and Conclusion: Currently, few musculoskeletal models include the popliteus muscle for kinematic and kinetic studies of the knee. The role of the popliteus muscle in knee mechanics and balancing should not be underestimated and merits inclusion into computational knee models and joint simulations. The ratio of popliteus PCSA to semimembranosus PCSA was 1:2.35 in females and 1:3.03 in males with an overall ratio of 1:2.69 irrespective of sex. These ratios, combined with the orientation of the popliteus, infer that the muscle plays a significant role in force generation across the knee joint. These findings also illustrate the need for subject-specific PCSA to be calculated for more reliable modelling due to the wide degree of muscular variation being present.Item Resident Total Knee Arthroplasty Training: The Protective Benefits of an Osteotome during Cruciate Retaining TKA(2016-03-23) Rabbani, Tebyan; Wood, Addison; Wagner, Russell MD; Sheffer, BenjaminResident Total Knee Arthroplasty Training: The Protective Benefits of an Osteotome during Cruciate Retaining TKA INTRODUCTION: The central objective of this study is to evaluate the effectiveness of a simple surgical technique to prevent PCL damage during performance of a posterior cruciate retaining (CR) total knee arthroplasty (TKA) surgery. This technique involves placement of an osteotome to prevent iatrogenic injury to the PCL by the sagittal saw blade during tibial resection. This simple technique can be useful to faculty members instructing novice residents or to senior surgeons looking to perform a low volume of CR TKA as an adjunct to their private practices. METHODS: We randomized 60 cadaveric specimens into two groups: Group I and Group II. Group I, 30 specimens, received standard tibial resections as performed during CR-TKA using a standard Y shaped PCL retractor. Group II, 30 specimens, received standard tibial resections as performed during CR-TKA using a standard Y shaped PCL retractor with the additional placement of a ½ inch osteotome. A board certified adult reconstructive orthopaedic surgeon, aligned the extramedullary tibial resection guide and positioned the osteotome. Posterior cruciate ligaments were assessed after completion of the procedures and removal of all instrumentation by 3 separate individuals to assess PCL damage. There were two states defined: PCL intact and PCL damaged. RESULTS: A difference in PCL damage was noted in 73% (22/30) of group I and in 23% (7/30) of group II. Group I was found to be twice more likely to have an injured PCL than Group II which used an osteotome for PCL protection. DISCUSSION AND CONCLUSION: Placement of an osteotome anterior to the PCL during CR-TKA provides a protective benefit to the patient. We speculate that the protective benefit could be increased by ensuring osteotome penetration is deeper than resection depth. This study simulated 60 tibial resections and may be applied to novice resident training.Item The Combined Effect of Translational and Rotational Malreduction on Sacroiliac Joint Contact Surface Area(2016-03-23) Wood, Addison; Wagner, Russell; Barcak, Eric; Lopez, JenniferPURPOSE: Boney apposition of sacroiliac articular surfaces or anatomic reduction is of paramount importance to achieve long term stabilization through fusion of the sacroiliac joint. The amount of contact surface area in these fixated joints provides some insight into the potential fusion rates of a joint. There is a bulk of literature supporting an association between anatomic reduction and good long term outcomes, yet most of these studies define an acceptable reduction as having less than 1 cm of displacement which would be unacceptable in other areas of the skeletal system. METHODS: 14 sacroiliac joints specimens were dissected prior to scanning each face of the sacroiliac joint with a multi laser 3D scanner (NextEngine, Inc,). The 3D models were then imported into AutoCAD modeling software (Autodesk, Inc,) for manipulation. Prior to manipulation, the major and minor axes of the sacroiliac joint are defined and used as pathways for superior, posterosuperior, and posterior displacements of the sacrum on the ilium. In addition, a vertical axis as served as the center of internal and external rotation manipulations. Contact surface area for each specimen was then calculated while in the fully anatomically reduced state. This measurement was repeated as the sacrum was displaced in 2mm increments, up to maximum of 25mm, separately in all 3 translational directions. This method was repeated and contact surface area measurements recorded as the ilium was rotated internally and externally in 1 degree increments, up to maximum of 10 degrees, at each increment of translational displacement. RESULTS: Work in progress, however, all 14 specimens have been scanned with a 3D laser scanner and data collection is underway. DISCUSSION AND CONCLUSION: Current literature has only addressed planar translations of the ilia in relation to the sacrum. This is in stark contrast to the reality of typical sacroiliac disruptions which involve multiple translations in combination with internal/external rotation of the ilia. Therefore, the goal of this study was to evaluate the acceptable tolerances of malreduced sacroiliac joints through contact surface area changes in response to combined translations and rotations about the sacroiliac joint. By overcoming the limitations of prior 2 dimensional comparisons we provide a clearer picture of the necessity of anatomic reduction and the need for increased aggressiveness in the treatment of sacroiliac disruptions through our 3D study.Item Three-Dimensional Comparison of Fibular Motion After Syndesmosis Fixation Using Combined Suture-Button and Internal Brace Constructs(2019-03-05) Wood, Addison; Seyed, Arshad; Stewart, Donald; kim, hannahPurpose The purpose of this study was to evaluate the ability of an internal brace to add sagittal plane translational and transverse plane rotational constraint to suture-button constructs with syndesmosis injuries. Methods 11 Fresh frozen cadaver ankles were stressed in external rotation using a custom-made ankle rig. Each ankle had simultaneous recording of ultrasound video, 6 DOF kinematics of fibula and tibia, and torque as the ankle was stressed by an examiner. The ankles were tested in 6 different states: 1. Native uninjured 2. Injured with IOL and AITFL sectioned 3. 1x Suture-button 4. 2x Suture-buttons, divergent 5. 1x Internal Brace with 2x Suture-buttons, divergent 6. 1x Internal Brace with 1x Suture-buttons Results Only the internal brace + 2x suture-buttons and internal brace + 1x suture-button constructs were found to be significantly different than the injured state (P=.0003, P=.002) with mean external rotation of the fibula. Conclusion Overall, the most important finding of this study was the addition of an internal brace to suture-button constructs provided a mechanism to increase external rotational constraint of the fibula. This study provides a mechanistic understanding of how the combined suture-button and internal brace construct provides an anatomically similar reconstruction of constraints found in the native ankle. However, none of the constructs examined in this study were able to fully restore physiologic motion.