Conor Murphy

Three-Dimensional Analysis of Fibular Motion After Fixation of Syndesmotic Injuries With a Screw or Suture-Button Construct

Background: Suture-button constructs are an alternative to screw fixation for syndesmotic injuries, and proponents advocate that suture-button constructs may allow physiological motion of the syndesmosis. Recent biomechanical data suggest that fibular instability with syndesmotic injuries is greatest in the sagittal plane, but the design of a suture-button construct, being a rope and 2 retention washers, is most effective along the axis of the rope (in the coronal plane). Some studies report that suture-button constructs are able to constrain fibular motion in the coronal plane, but the ability of a tightrope to constrain sagittal fibular motion is unknown. The purpose of this study was to assess fibular motion in response to an external rotation stress test in a syndesmotic injury model after fixation with a screw or suture-button constructs. Methods: Eleven fresh-frozen cadaver whole legs with intact tibia-fibula articulations were secured to a custom fixture. Fibular motion (coronal, sagittal, and rotational planes) in response to a 6.5-Nm external rotation moment applied to the foot was recorded with fluoroscopy and a high-resolution motion capture system. Measures were taken for the following syndesmotic conditions: intact, complete lateral injury, complete lateral and deltoid injury, repair with a tetracortical 4.0-mm screw, and repair with a suture button construct (Tightrope; Arthrex, Naples, FL) aimed from the lateral fibula to the anterior medial malleolus. Results: The suture-button construct allowed significantly more sagittal plane motion than the syndesmotic screw. Measurements acquired with mortise imaging did not detect differences between the intact, lateral injury, and 2 repair conditions. External rotation of the fibula was significantly increased in both injury conditions and was not restored to intact levels with the screw or the suture-button construct. Conclusion: A single suture-button placed from the lateral fibula to the anterior medial malleolus was unable to replicate the motion observed in the intact specimen when subjected to an external rotation stress test and allowed significantly more posterior motion of the fibula than when fixed with a screw in simulated highly unstable injuries. Clinical Relevance: Fixation of a syndesmotic injury with a single suture-button construct did not restore physiological fibular motion, which may have implications for postoperative care and clinical outcomes.

Effect of Complete Syndesmotic Disruption and Deltoid Injuries and Different Reduction Methods on Ankle Joint Contact Mechanics

Background: Syndesmotic injuries can be associated with poor patient outcomes and posttraumatic ankle arthritis, particularly in the case of malreduction. However, ankle joint contact mechanics following a syndesmotic injury and reduction remains poorly understood. The purpose of this study was to characterize the effects of a syndesmotic injury and reduction techniques on ankle joint contact mechanics in a biomechanical model. Methods: Ten cadaveric whole lower leg specimens with undisturbed proximal tibiofibular joints were prepared and tested in this study. Contact area, contact force, and peak contact pressure were measured in the ankle joint during simulated standing in the intact, injured, and 3 reduction conditions: screw fixation with a clamp, screw fixation without a clamp (thumb technique), and a suture-button construct. Differences in these ankle contact parameters were detected between conditions using repeated-measures analysis of variance. Results: Syndesmotic disruption decreased tibial plafond contact area and force. Syndesmotic reduction did not restore ankle loading mechanics to values measured in the intact condition. Reduction with the thumb technique was able to restore significantly more joint contact area and force than the reduction clamp or suture-button construct. Conclusion: Syndesmotic disruption decreased joint contact area and force. Although the thumb technique performed significantly better than the reduction clamp and suture-button construct, syndesmotic reduction did not restore contact mechanics to intact levels. Clinical Relevance: Decreased contact area and force with disruption imply that other structures are likely receiving more loads (eg, medial and lateral gutters), which may have clinical implications such as the development of posttraumatic arthritis.

Biomechanical Analysis of Suture Anchor vs Tenodesis Screw for FHL Transfer

Background: Chronic Achilles injury is often treated with flexor hallucis longus (FHL) tendon transfer to the calcaneus using 1 or 2 incisions. A single incision avoids the risks of extended dissections yet yields smaller grafts, which may limit fixation options. We investigated the required length of FHL autograft and biomechanical profiles for suture anchor and biotenodesis screw fixation. Methods: Single-incision FHL transfer with suture anchor or biotenodesis screw fixation to the calcaneus was performed on 20 fresh cadaveric specimens. Specimens were cyclically loaded until maximal load to failure. Length of FHL tendon harvest, ultimate load, stiffness, and mode of failure were recorded. Results: Tendon harvest length needed for suture anchor fixation was 16.8 ± 2.1 mm vs 29.6 ± 2.4 mm for biotenodesis screw (P = .002). Ultimate load to failure was not significantly different between groups. A significant inverse correlation existed between failure load and donor age when all specimens were pooled (ρ = −0.49, P < .05). Screws in younger specimens (fewer than 70) resulted in significantly greater failure loads (P < .03). No difference in stiffness was found between groups. Modes of failure for screw fixation were either tunnel pullout (n = 6) or tendon rupture (n = 4). Anchor failure occurred mostly by suture breakage (n = 8). Conclusion: Adequate FHL tendon length could be harvested through a single posterior incision for fixation to the calcaneus with either fixation option, but suture anchor required significantly less graft length. Stiffness, fixation strength, and load to failure were comparable between groups. An inverse correlation existed between failure load and donor age. Younger specimens with screw fixation demonstrated significantly greater failure loads. Clinical Relevance: Adequate harvest length for FHL transfer could be achieved with a single posterior incision. There was no difference in strength of fixation between suture anchor and biotenodesis screw.

Particulated Juvenile Articular Cartilage Allograft Transplantation With Bone Marrow Aspirate Concentrate for Treatment of Talus Osteochondral Defects

Osteochondral defects (OCDs) of the talus are potential sequelae of traumatic ankle injury and chronic ankle instability. Conservative treatment may fail thus requiring surgical intervention. Primary surgical intervention has classically entailed bone marrow stimulation, which may include drilling, microfracture, and/or abrasion arthroplasty, filling in the defect with fibrocartilage. Clinical data has revealed good short-term success but the long-term effects and followup have been questioned. Newer techniques, such as osteochondral autograft transfer, fresh osteochondral allograft transfer, and autologous chondrocyte implantation, have shown initial promise in restoring physiological hyaline cartilage but each procedure carries increased morbidity as arthrotomy, osteotomy, or a second procedure are often necessary. Juvenile articular cartilage allograft transplantation has shown initial promising results in treating smaller sized OCDs and restoring physiological hyaline cartilage without the increased morbidity of osteotomy or 2-step procedures. Augmentation with biological adjuncts has been shown to further aid in healing and regeneration of physiological articular cartilage. The purpose of this article is to describe a novel surgical all-arthroscopic technique for transplantation of juvenile articular cartilage allograft augmented with bone marrow aspirate concentrate for the treatment of OCDs. Level of Evidence: Diagnostic Level 4. See Instructions for Authors for a complete description of levels of evidence.

Multiplanar CT Analysis of Fifth Metatarsal Morphology Implications for Operative Management of Zone II Fractures

Background: Percutaneous internal fixation is currently the method of choice treating proximal zone II fifth metatarsal fractures. Complications have been reported due to poor screw placement and inadequate screw sizing. The purpose of this study was to define the morphology of the fifth metatarsal to help guide surgeons in selecting the appropriate screw size preoperatively. Methods: Multiplanar analysis of fifth metatarsal morphology was completed using computed tomographic (CT) scans from 241 patients. Specific parameters were analyzed and defined in anteroposterior (AP), lateral, and oblique views including metatarsal length, distance from the base to apex of curvature, apex medullary canal width, apex height, and fifth metatarsal angle. Results: The average metatarsal length in the AP view was 71.4 ± 6.1 mm and in the lateral view 70.4 ± 6.0 mm, with 95% of patients having lengths between 59.3 and 83.5 mm and 58.4 and 82.4 mm, respectively. The average canal width at the apex of curvature was 4.1 ± 0.9 mm in the AP view and 5.3 ± 1.1 mm in the lateral view, with 95% of patients having widths between 2.2 and 5.9 mm and 3.2 and 7.5 mm, respectively. Average distance from apex to base was 42.6 ± 5.8 mm in the AP and 40.4 ± 6.4 mm in the lateral views. Every measurement taken in all 3 views had a significant correlation with height. Conclusions: When determining screw length, we believe lateral radiographs should be used since the distance from the base of the metatarsal to the apex was smaller in the lateral view. On average, the screw should be 40 mm or less to reduce risk of distraction. For screw diameter, the AP view should be used because canal shape is elliptical, and width was found to be significantly smaller in the AP view. Most canals can accommodate a 4.0- or 4.5-mm-diameter screw, and one should use the largest diameter screw possible. Larger individuals were likely to have more bowing in their metatarsal shaft, which may lead to a higher tendency to distract. Level of Evidence: Level III, comparative series.

Plantar-Plate Disruptions: “The Severe Turf-Toe Injury.” Three Cases in Contact Athletes

OBJECTIVE To present 3 cases of plantar-plate rupture and turf-toe injury in contact athletes at 1 university and to discuss appropriate diagnosis and treatment algorithms for each case. BACKGROUND Turf toe is a common injury in athletes participating in outdoor cutting sports. However, it has been used as an umbrella term to describe many different injuries of the great toe. In some cases, the injury can be so severe that the plantar plate and sesamoid apparatus may be ruptured. These patients may be better managed with surgery than with traditional nonoperative interventions. DIFFERENTIAL DIAGNOSIS Turf toe, plantar-plate disruption, sesamoid fracture. TREATMENT For stable injuries in which the plantar plate is not completely disrupted, nonoperative treatment with casting or a stiff-soled shoe, gradual weight bearing, and rehabilitation is the best practice. Unstable injuries require surgical intervention and plantar-plate repair. UNIQUENESS Turf toe and injury to the first metatarsophalangeal joint are relatively common injuries in athletes, but few researchers have detailed the operative and nonoperative treatments of plantar-plate disruption in these patients. We examine 3 cases that occurred over 4 seasons on a collegiate football team. CONCLUSIONS Turf toe represents a wide array of pathologic conditions involving the first metatarsophalangeal joint. Stress and instability testing are key components to assess in determining whether surgical intervention is warranted to restore optimal function. Stiffer-soled shoes or shoes with steel-plate insertions may help to prevent these injuries and are useful tools for protection during the rehabilitation period.

Return to Play After Complex Knee Injuries: Return to Play After Medial Collateral Ligament Injuries

The medial collateral ligament is the most commonly injured knee ligament in professional footballers. Injuries are the result of a valgus force being imparted onto the knee joint usually after contact with another player or object. Given its extra-articular location, the medial collateral ligament has a high propensity to heal with non-operative treatment, but surgical treatment is warranted in select situations. A high index of suspicion for concurrent injuries to other knee structures is paramount as this significantly impacts treatment decisions. Irrespective of non-operative or operative treatment, structured rehabilitation protocols are critical to the successful management of these injuries. This chapter will provide a comprehensive guide to the diagnosis and management of medial collateral ligament injuries with a focus on safe return to play in football.

Passive teaching is not as effective as active teaching for learning the standard technique of pivot shift test

Objective Two major teaching methods available for learning the pivot shift test are active teaching with real-time feedback from an instructor and passive teaching through the use of instructional textbooks or videos. The purpose of this study was to determine the effect of active and passive teaching methods on the execution of the proper technique of the pivot shift test. Methods Six orthopaedic surgery residents each performed 110 pivot shift tests on a fresh-frozen, cadaveric pelvis-to-toe specimen with anterior cruciate ligament insufficiency and lateral meniscectomy. Participants performed 10 repetitions before teaching and a total of 100 repetitions after either active or passive teaching. Six degree-of-freedom kinematics of the knee defined by the Grood/Suntay coordinate system were recorded after every fifth repetition using an electromagnetic tracking system. Anterior/posterior translation of the lateral knee compartment during the reduction event was also quantified. Depending on the normality of the data, a two-tailed t-test or Wilcoxon rank-sum test was used for comparisons of kinematics between the active and passive teaching groups and between successful and unsuccessful trials within each teaching group. Statistical significance was set at p<0.05. Results The success rate after active teaching was 31.7% compared with 30.0% after passive teaching. However, the starting position of the reduction event in the active teaching group was rotated by more than twice the amount of valgus rotation compared with the passive group (7.4°±3.3° vs 3.0°±2.7°; p<0.001). During the reduction event, the active teaching group underwent 4.4°±5.6° of external rotation, which is 10.6° in the opposite direction of the passive group (6.2°±4.8° of internal rotation; p<0.001). Conclusion Successful pivot shift tests can be performed after passive teaching, but the standard technique is not as effectively learnt through passive teaching since traditional external rotation during the reduction event was not used as in the active teaching group. Level of evidence V.

Syndesmotic Injury Assessment With Lateral Imaging During Stress Testing in a Cadaveric Model

Background: External rotation, lateral, and sagittal stress tests are commonly used to diagnose syndesmotic injuries, but their efficacy remains unclear. The purpose of this study was to characterize applied stresses with fibular motion throughout the syndesmotic injury spectrum. We hypothesized that sagittal fibular motion would have greater fidelity in detecting changes in syndesmotic status compared to mortise imaging. Methods: Syndesmotic instability was characterized using motion analysis during external rotation, lateral, and sagittal stress tests on cadaveric specimens (n = 9). A progressive syndesmotic injury was created by sectioning the tibiofibular and deltoid ligaments. Applied loads and fibular motion were synchronously measured using a force transducer and motion capture, respectively, while mortise and lateral radiographs were acquired to quantify clinical measurements. Fibular motion in response to these 3 stress tests was compared between the intact, complete lateral syndesmotic injury and lateral injury plus a completely sectioned deltoid condition. Results: Stress tests performed under lateral imaging detected syndesmotic injuries with greater sensitivity than the clinical-standard mortise view. Lateral imaging was twice as sensitive to applied loads as mortise view imaging. Specifically, half as much linear force generated 2 mm of detectable syndesmotic motion. In addition, fibular motion increased linearly in response to sagittal stresses (Pearson’s r [ρ] = 0.91 ± 0.1) but not lateral stresses (ρ = 0.29 ± 0.66). Conclusion: Stress tests using lateral imaging detected syndesmotic injuries with greater sensitivity than a typical mortise view. In addition to greater diagnostic sensitivity, reduced loads were required to detect injuries. Clinical Relevance: Syndesmotic injuries may be better diagnosed using stress tests that are assessed using lateral imaging than standard mortise view imaging.

Anterior-Posterior Translation and Axial Rotation of the Fibula are Significantly Increased with Sequential Disruption of the Syndesmosis

Category: Ankle, Sports, Trauma Introduction/Purpose: Injury to the Anterior inferior tibiofibular ligament (AITFL), Posterior inferior tibiofibular ligament (PITFL) and Interosseus membrane (IOM) predicts residual symptoms in ankle sprains. Limited kinematic knowledge of the tibiofibular joint results in missed diagnosis and poor clinical outcomes. Lateral fibular displacement on radiologic assessment signifies syndesmotic disruption which dictates operative management. Previous studies demonstrated that fibular motion is multiplanar after injury. The objective of this study is to determine increases in fibular motion with sequential syndesmotic injury and the contribution of the AITFL. Methods: Five fresh-frozen human cadaveric tibial plateau-to-toe specimens with a mean age of 58 years (range 38-73 years) were tested using a 6-degree-of-freedom robotic testing system. The tibia and calcaneus were rigidly fixed. The subtalar joint was fused. The full fibular length was maintained and fibular motion was unconstrained. A 5 Nm external rotation and 5 Nm inversion moment were applied to the ankle at 0°, 15°, and 30° plantarflexion and 10° dorsiflexion. The motion of the fibula was tracked by a 3D optical tracking system. Outcome variables included fibular medial-lateral (ML) translation, anterior-posterior (AP) translation, and external rotation (ER) during each applied moment and flexion angle in the following conditions: 1) intact ankle, 2) AITFL transected, 3) PITFL and IOM transected. Statistical analysis included an ANOVA with a post-hoc Tukey analysis to compare the changes in fibular motion between the intact and injury models at each applied moment and flexion angle (*p<0.05). Results: The only significant differences in fibular motion were during the 5 Nm inversion moment. The posterior translation of the fibula was significantly greater with AITFL injury compared to the intact ankle at 15° and 30° plantarflexion. Significant increases in posterior translation between the intact ankle and AITFL, PITFL, and IOM injury existed at 0°, 15°, and 30° plantarflexion. No significant motion differences were observed between the AITFL injury and combined injury at any condition. When comparing the intact ankle and combined injury, significant increases in ER existed at 0° and 30° plantarflexion and 10° dorsiflexion. The only significant difference in ER between the intact ankle and AITFL injury existed at 0° plantarflexion. Conclusion: This study showed that transecting the AITFL resulted in the largest increases in fibular motion with only minimal further increases after complete syndesmotic injury. Fibular displacement was primarily in the sagittal plane. This study utilized a novel setup with unconstrained motion in a full length, intact fibula. Measuring ML translation alone could underestimate sagittal and rotational instability of the syndesmosis in AITFL injuries. Evaluating fibular AP translation and ER are not part of current standard diagnostic protocols. Physicians may consider more aggressive treatment of isolated AITFL injuries.