Broström ankle ligament repair augmented with suture tape : Results of magnetic resonance imaging evaluation.

BACKGROUND: The Broström procedure is an established procedure in cases of primary lateral ankle ligament repair (LALR). To improve postoperative stability an augmentation device, InternalBrace™ (Arthrex, Naples, FL) has been introduced. This study evaluates remodelling of the anterior talofibular ligament (ATFL) in patients undergoing a tape augmented Broström technique as well as clinical outcomes. METHODS: In this study 32 patients with chronic lateral ankle instability (CLAI) receiving augmented LALR were included. Clinical outcomes were evaluated at a one-time postoperative visit between 12 and 18 months. A 3 T magnetic resonance imaging (MRI) was done to evaluate the morphology of the ATFL. Statistical analysis was completed with the free software and environment R version 3.6.3 (Bell Laboratories, Murray Hill, NJ, USA) and P-values < 0.05 were considered statistically significant. RESULTS: The mean follow-up time was 15.3 ± 1.8 months with a return to sport time of 4.0 ± 2.4 months. The average AOFAS (American Orthopaedic Foot and Ankle Society Score) score was 94.4 ± 7.2, the FAOS (Foot and Ankle Outcome Score) demonstrated 87.3 ± 10.4 points and the FFI (Foot Function Index - 2 scores (pain and function score)) was 22.9 ± 20.1 and 15.4 ± 10.4, respectively. The MRI findings demonstrated an average length of the ATFL of 18.6 ± 4.3 mm and the width was 3.6 ± 0.9 mm. A clear differentiation between the ATFL and the augmentation device could be shown in 28 cases. The Fisher's exact test could not depict a significant correlation between the presence of a bone marrow edema and the tension of the augmentation device with a level of significance of α = 0.05. CONCLUSION: An anatomical healing tendency of the ligament repair and good integrity of the augmentation device could be shown based on MRI findings. The lateral ligament repair augmented with suture tape is an effective and safe procedure regarding surgical treatment in chronic lateral ankle instability producing good clinical outcome.

The proteolysis of ZP proteins is essential to control cell membrane structure and integrity of developing tracheal tubes in Drosophila.

Membrane expansion integrates multiple forces to mediate precise tube growth and network formation. Defects lead to deformations, as found in diseases such as polycystic kidney diseases, aortic aneurysms, stenosis, and tortuosity. We identified a mechanism of sensing and responding to the membrane-driven expansion of tracheal tubes. The apical membrane is anchored to the apical extracellular matrix (aECM) and causes expansion forces that elongate the tracheal tubes. The aECM provides a mechanical tension that balances the resulting expansion forces, with Dumpy being an elastic molecule that modulates the mechanical stress on the matrix during tracheal tube expansion. We show in Drosophila that the zona pellucida (ZP) domain protein Piopio interacts and cooperates with the ZP protein Dumpy at tracheal cells. To resist shear stresses which arise during tube expansion, Piopio undergoes ectodomain shedding by the Matriptase homolog Notopleural, which releases Piopio-Dumpy-mediated linkages between membranes and extracellular matrix. Failure of this process leads to deformations of the apical membrane, tears the apical matrix, and impairs tubular network function. We also show conserved ectodomain shedding of the human TGFß type III receptor by Notopleural and the human Matriptase, providing novel findings for in-depth analysis of diseases caused by cell and tube shape changes.

Biomechanical evaluation of the proximal chevron osteotomy in comparison to the Lapidus arthrodesis for the correction of hallux valgus deformities.

PURPOSE: The proximal chevron osteotomy and the modified Lapidus arthrodesis are both procedures utilized for deformity correction in patients with severe symptomatic hallux valgus. The aim of the current study was to compare their biomechanical stability when using locking plate fixation. METHODS: Twelve matched pairs of human anatomical lower leg specimens underwent on one side a proximal chevron osteotomy with a medial locking plate and on the other side a modified Lapidus arthrodesis with a plantar locking plate utilizing an interfragmentary compression screw. All specimens underwent bone mineral density (BMD) assessment and were tested in a servohydraulic load frame which applied a load on the centre of the metatarsal head over 1000 loading cycles with subsequently ultimate load testing. Displacement of the proximal and distal bone segment, ultimate load, and bending stiffness were analyzed. RESULTS: Mean displacement of both procedures showed no statistically significant difference throughout all the loading cycles (0.213 ≤ p ≤ 0.834). The mean ultimate load of the proximal chevron osteotomy was 227.9 N (± 232.4) and of the modified Lapidus arthrodesis 162.9 N (± 74.6) (p = 0.754). The proximal chevron osteotomy (38.2 N/mm (± 24.9)) had a significantly higher bending stiffness compared to the modified Lapidus arthrodesis (17.3 N/mm (± 9.9)) (p = 0.009). There was no correlation between BMD and displacement in all loading cycles, ultimate load, and bending stiffness of either procedure (p > 0.05). CONCLUSION: Although the bending stiffness of the chevron osteotomy was higher, there was no statistically significant difference between the surgical techniques in mean displacement and ultimate load. The BMD did not influence the overall stability of either reconstruction. Locking plate fixation increases the clinical value of the modified Lapidus arthrodesis by outweighing most of the biomechanical disadvantages in comparison to the proximal chevron osteotomy.

Arthroscopic accessibility of the first metatarsophalangeal joint for osteochondral defects of the metatarsal head by two-portal technique - comparing joint distraction and plantarflexion.

BACKGROUND: Several techniques and approaches for first metatarsophalangeal (MTP1) joint arthroscopy have been reported, where joint accessibility plays a key role. This study aimed to evaluate differences in arthroscopic accessibility of the first metatarsal head (MTH1) comparing non-invasive distraction and maximum plantarflexion in a two-portal approach. METHODS: Forty fresh-frozen lower leg specimens were included and divided into a distraction group (D-group) and a plantarflexion group (PF-group). A two-portal technique (1.9 mm-30°-scope) was used for arthroscopy, maximum reach at the MTH1 was marked. Following arthroscopy, specimens were dissected and examined for iatrogenic injuries. The reached area at the chondral surface was pinned and accessibility calculated. RESULTS: Accessibility of the MTH1 was 58.03 % ± 13.64 (D-group) and 55.93 % ± 10.30 (PF-group, p = 0.51). The dorsomedial hallucal nerve was injured in one specimen (2.5 %). CONCLUSION: Maximum plantarflexion showed no difference in arthroscopic MTP1 joint accessibility compared to non-invasive distraction in a two-portal approach. During dorsomedial portal placement, the dorsomedial hallucal nerve is at risk for iatrogenic injury.

All-arthroscopic reconstruction of the anterior talofibular ligament is comparable to open reconstruction: a systematic review.

The aim of this study was to determine whether all-arthroscopic repair would lead to improved clinical outcomes, lower complication rates, shorter postoperative immobilization and earlier return to activity compared to open Broström repair in the surgical treatment of chronic lateral ankle instability (CLAI). A systematic literature search was conducted using Pubmed and Embase to identify studies dealing with a comparison of outcomes between all-arthroscopic and open Broström repair for CLAI. The search algorithm was 'ankle instability' AND 'Brostrom' AND 'arthroscopic' AND 'open'. The study had to be written in English language, include a direct comparison of all-arthroscopic and open Broström repair to treat CLAI and have full text available. Exclusion criteria were former systematic reviews, biomechanical studies and case reports. Overall, eight studies met the inclusion criteria and were included in the analysis. Clinical outcomes did not differ substantially between patients treated with either arthroscopic or open Broström repair. Studies that reported on return to activity and sports following surgery suggested that patients that had all-arthroscopic Broström repair returned at a quicker rate. Overall complication rate tended to be lower after arthroscopic Broström repair. Similar to open repair, all-arthroscopic ligament repair for CLAI is a safe treatment option that yields excellent clinical outcomes. Level of Evidence: Level III evidence (systematic review of level I, II and III studies).

Improved Outcome and Earlier Return to Activity After Suture Tape Augmentation Versus Broström Repair for Chronic Lateral Ankle Instability? A Systematic Review.

PURPOSE: To determine whether the use of suture tape augmentation (ST) would lead to improved clinical outcomes, increased stability, shorter postoperative immobilization, and earlier return to activity and sports compared with Broström repair (BR) in surgical treatment of chronic lateral ankle instability (CLAI). METHODS: A systematic literature search was performed using Pubmed and Embase according to PRISMA guidelines. The following search terms were used: ankle instability, suture tape, fiber tape, and internal brace. Full-text articles in English that directly compared BR and ST cohorts were included, with a minimum cohort size of 40 patients. Exclusion criteria were former systematic reviews, biomechanical studies, and case reports. RESULTS: Ultimately, 7 clinical trials were included in this systematic review. Regarding the clinical and radiologic outcomes and complication rates, no major differences were detected between groups. Recurrence of instability and revision surgeries tended to occur more often after BR, whereas irritation of the peroneal nerve and tendons seemed to occur more frequently after ST. Postoperative rehabilitation protocols were either the same for both groups or more aggressive in the ST groups. When both techniques were performed with arthroscopic assistance, return to sports was significantly faster in the ST groups. CONCLUSIONS: In conclusion, suture tape augmentation showed excellent results and is a safe technique comparable to traditional Broström repair. No major differences regarding clinical and radiologic outcomes or complications were found. LEVEL OF EVIDENCE: III, systematic review of level I, II, and III studies.

Arthroscopically Assisted Tape Augmentation for Anterior Talofibular Ligament Repair.

In this Technical Note, we describe arthroscopically assisted tape augmentation of a modified Broström repair for chronic lateral ankle instability. Specifically, this technique involves talar anchor placement under direct arthroscopic visualization combined with a minimally invasive approach for anatomic anterior talofibular ligament repair and FiberTape (Arthrex, Naples, FL) augmentation. The primary advantage of our technique compared with open InternalBrace (Arthrex) techniques is that only a 2-cm incision is made and no subcutaneous suture passing and knot tying are required, which bear the danger of superficial peroneal nerve damage. In addition, the risk of nonanatomic anchor placement is diminished owing to direct arthroscopic visualization and preparation of the anterior talofibular ligament remnants.

Peroneus brevis as source of instability in Jones fracture fixation.

PURPOSE: Intramedullary screw fixation is currently considered the gold standard treatment for Jones fractures in the athlete. Besides biological factors (i.e., poor vascularization), mechanical instability induced by the pull of the peroneus brevis tendon (PBT) contributes to deficient Jones fracture healing. This biomechanical study aimed to simulate loads induced by the PBT at the fifth metatarsal and to compare the stability of two intramedullary screw constructs in a Jones fracture fixation model. METHODS: Jones fractures were created in 24 human paired specimens, and fixation was achieved with either a solid Jones fracture specific screw (JFXS) (Jones Screw; Arthrex Inc., Naples FL, USA) or a cannulated headless compression screw (HCS) (HCS; DePuySynthes, Solothurn, Switzerland). The PBT was fixed to a mechanical load frame by the use of a cryoclamp. Constructs were loaded in tension for 1000 cycles, followed by an ultimate load test. Construct failure was defined by exceeding 10° of dorsal angulation. RESULTS: Preliminary failure occurred more often in HCS constructs (33%) compared to JFXS constructs (0%) (P = 0.044). Mean tensile load to failure reached 123.8 ± 91.4 N in the JFXS group and 91.5 ± 62.2 N in the HCS group (P = 0.337). The mean slope of the load-displacement curve was 24.2 ± 10.4 N/mm for JFXS constructs and 24.7 ± 5.5 N/mm for HCS constructs, respectively (P = 0.887). CONCLUSION: This is the first study evaluating the effect of PBT pull on the mechanical stability of Jones fracture fixation. Higher preliminary failure rates of HCS were found under cyclic loading conditions compared to JFXS.

The tibialis posterior tendon footprint: an anatomical dissection study.

BACKGROUND: The tibialis posterior tendon (TPT) is the main dynamic stabilizer of the medial longitudinal arch of the foot. Especially in adult acquired flatfoot deformity (AAFD) the TPT plays a detrimental role. The pathology and function of the tendon have been extensively investigated, but knowledge of its insertional anatomy is paramount for surgical procedures. This study aimed to analyze the complex distal footprint anatomy of the TPT. METHODS: Forty-one human anatomical specimens were dissected and the distal TPT was followed to its bony footprints. After tendon removal the footprints were marked with ink. Standardized photographs were taken and consecutively analyzed by digital imaging measurements. Footprint length, width, area of insertion, location, and shape was studied regarding the main insertion at the navicular bone. RESULTS: All specimens had the main TPT insertion at the navicular bone (41/41, 100%). Sixty-three percent of navicular TPT insertions were located at the plantar aspect. The mean navicular footprint measured 12.1 mm × 6.9 mm in length and width, respectively. The tendon further spread into several slips which anchored the tibialis posterior deep in the plantar arch. TPT insertions were highly variable with an involvement of up to eight distinct bony footprints in the mid- and hindfoot. The second most common additional footprint was the lateral cuneiform (93% of dissected feet), followed by the medial cuneiform (80%), the metatarsal bases [1-5] (80%), the cuboid (46%), the intermediate cuneiform (19%), and the calcaneus (12%). CONCLUSIONS: The present study adds to current knowledge on the footprint anatomy of the TPT. Based on the findings of this study we advocate a plantar location of flexor digitorum longus tendon transfer in flexible AAFD in order to restore the anatomical lever and insertion of the TPT.

The bicistronic gene würmchen encodes two essential components for epithelial development in Drosophila.

Epithelial tissues are fundamental for the establishment and maintenance of different body compartments in multicellular animals. To achieve this specific task epithelial sheets secrete an apical extracellular matrix for tissue strength and protection and they organize a transepithelial barrier function, which is mediated by tight junctions in vertebrates or septate junctions in invertebrates. Here, we show that the bicistronic gene würmchen is functionally expressed in epithelial tissues. CRISPR/Cas9-mediated mutations in both coding sequences reveal two essential polypeptides, Würmchen1 and Würmchen2, which are both necessary for normal epithelial tissue development. Würmchen1 represents a genuine septate junction core component. It is required during embryogenesis for septate junction organization, the establishment of a transepithelial barrier function, distinct cellular transport processes and tracheal system morphogenesis. Würmchen2 is localized in the apical membrane region of epithelial tissues and in a central core of the tracheal lumen during embryogenesis. It is essential during the later larval development.

Radiographic Sagittal Tibio-Talar Offset in Ankle Arthrodesis-Accuracy and Reliability of Measurements.

Radiographic outcome assessment of ankle arthrodesis (AA) requires accurate measurement techniques. This study aimed to identify the most reliable methods for sagittal tibio-talar alignment measurements with regard to the tibio-talar offset after AA. Lateral weight-bearing radiographs of 38 fused ankles were selected for retrospective review. The sagittal tibio-talar angle (STTA), the modified tibio-talar ratio (mT-T ratio) and the sagittal tibio-talar offset (tibCOR, procLAT) were measured by three independent observers. Intra- and interobserver correlation coefficients (ICC) and mean measurement differences were calculated to assess measurement reliability and accuracy. By defining the talar longitudinal axis as a line from the inferior aspect of the posterior tubercle of the talus to the most inferior aspect of the talar neck, STTA showed excellent (ICC 0.924; CI 95% 0.862-0.959) and mTT-ratio provided high (ICC 0.836; CI 95% 0.721-0.909) interobserver reliability, respectively. For tibio-talar offset measurement the tibCOR method showed superior reliability and better interobserver agreement compared to the procLAT technique. The STTA and a modified T-T ratio are recommended for future scientific radiographic measurements in AA.

Evaluation of Two Types of Intramedullary Jones Fracture Fixation in a Cyclic and Ultimate Load Model.

Implant choice is a matter of concern in athletes and active patients who sustain a Jones fracture because they are prone to failure including non-union, screw failure, and refracture. The aim of this study was to compare the biomechanical behavior of a Jones fracture-specific screw (JFXS) with a cannulated headless compression screw (HCS) in a simulated partial weight-bearing and ultimate load Jones fracture fixation model. Ten matched pairs of human anatomical specimens underwent Jones fracture creation and consecutive intramedullary stabilization with a solid JFXS or a cannulated HCS. The bone mineral density was assessed prior to testing. Cyclic plantar to dorsal loading was applied for 1000 cycles, followed by load to failure testing. Angulation was measured by an opto-electronic motion capture system and mode of failure classification was determined by video analysis. Paired analysis showed no statistically significant difference between both screw constructs. Ultimate load reached 236.9 ± 107.8 N in the JFXS group compared with 210.8 ± 150.7 N in the HCS group (p = 0.429). The bone mineral density correlated positive with the pooled ultimate load (R = 0.580, p = 0.007) for all constructs and negatively with angulation (R = -0.680, p = 0.002) throughout cyclic loading. Solid fracture-specific and cannulated headless compression screws provide equal ultimate loads and stiffness for Jones fracture fixation. A low bone mineral density significantly impairs the construct stability and the ultimate load of both intramedullary screw constructs. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 38:911-917, 2020.

Accessibility to Talar Dome in Neutral Position, Dorsiflexion, or Noninvasive Distraction in Posterior Ankle Arthroscopy.

BACKGROUND: Osteochondral lesions of the talus are frequent pathologies of the ankle joint. Especially through arthroscopy, the treatment is kept as minimally invasive as possible. However, there are some drawbacks as to the reachability because of the high congruency of the ankle joint. Here, either noninvasive distraction or maximal dorsiflexion may be an option for better access to the lesion. The purpose of this study was to evaluate maximal dorsiflexion compared to neutral position or noninvasive distraction of the ankle joint in the arthroscopic reachability of the talar dome. The hypothesis of this study was that maximal dorsiflexion would allow for greater accessibility of the talar dome compared to neutral position or noninvasive distraction of the joint. METHODS: Twenty matched pairs (n=40) of anatomical ankle specimens were used. The effects of neutral position, maximal dorsiflexion, and noninvasive distraction of the ankle joint on arthroscopic accessibility of the ankle joint were tested. After disarticulation of the talus, reach was measured and compared between the 3 positions. RESULTS: In neutral position, 13.7±1.2 mm of the talar dome was reached laterally and 14.0±1.0 mm medially. In maximal dorsiflexion, the distance was 19.0±1.1mm laterally and 19.8±1.4 mm medially, and in noninvasive distraction it was 16.1±1.5 mm laterally and 15.7±1.0 mm medially. The statistical comparison showed a significantly better reach in dorsiflexion laterally (P = .003) and medially (P = .026). CONCLUSION: Accessibility of the talar dome in maximal dorsiflexion was superior to that in neutral position or noninvasive distraction. CLINICAL RELEVANCE: Results of this study may allow for better planning in arthroscopic treatment of osteochondral lesions of the talus.

Biomechanical evaluation of different ankle orthoses in a simulated lateral ankle sprain in two different modes.

Ankle orthoses are commonly used for prevention of recurrent ankle sprains. While there are some data on their functional performance or restriction of range of motion, there is little knowledge on the quantifiable passive mechanical effectiveness of various devices. This study aimed to determine the prophylactic stabilization effect for commonly prescribed ankle orthoses in a simulated recurrent ankle sprain. Eleven anatomic lower leg specimens were tested in plantar flexion and hindfoot inversion in a simulated ankle sprain in a quasi-static and dynamic test mode at 0.5°/s and 50°/s internal rotation, respectively. Tests included intact specimens, same specimens with the ruptured anterior talofibular ligament (ATFL), followed by stabilization with five different semi-rigid orthoses: AirGo Ankle Brace, Air Stirrup Ankle Brace, Dyna Ankle 50S1, MalleoLoc, and Aequi. Compared to the injured and unprotected state, two orthoses (AirGo and Air Stirrup) significantly reinforced the ankle. The Aequi ankle brace restored stability comparable to an intact joint. Dyna Ankle 50S1 and MalleoLoc provided insufficient resistance to applied internal rotation compared to the ankle with ruptured ATFL. Ankle orthoses varied significantly in their ability to stabilize the unstable ankle during an ankle sprain in both testing modes. Presented objective data on passive stabilization reveal a lack of supporting evidence for clinical application of ankle orthoses.

Conserved function of the matriptase-prostasin proteolytic cascade during epithelial morphogenesis.

Extracellular matrix (ECM) assembly and remodelling is critical during development and organ morphogenesis. Dysregulation of ECM is implicated in many pathogenic conditions, including cancer. The type II transmembrane serine protease matriptase and the serine protease prostasin are key factors in a proteolytic cascade that regulates epithelial ECM differentiation during development in vertebrates. Here, we show by rescue experiments that the Drosophila proteases Notopleural (Np) and Tracheal-prostasin (Tpr) are functional homologues of matriptase and prostasin, respectively. Np mediates morphogenesis and remodelling of apical ECM during tracheal system development and is essential for maintenance of the transepithelial barrier function. Both Np and Tpr degrade the zona pellucida-domain (ZP-domain) protein Dumpy, a component of the transient tracheal apical ECM. Furthermore, we demonstrate that Tpr zymogen and the ZP domain of the ECM protein Piopio are cleaved by Np and matriptase in vitro. Our data indicate that the evolutionarily conserved ZP domain, present in many ECM proteins of vertebrates and invertebrates, is a novel target of the conserved matriptase-prostasin proteolytic cascade.

Comparison of Plantar Pressure Distribution and Functional Outcome after Scarf and Austin Osteotomy.

OBJECTIVE: To investigate the changes of plantar pressure distribution in patients who underwent either Austin or Scarf osteotomy and underwent a postoperative rehabilitation program. METHODS: Between September 2006 and December 2007, 50 participants who suffered from mild to moderate hallux valgus deformity were prospectively included in this study. An Austin osteotomy (Austin group) was performed in 25 patients and a Scarf osteotomy (Scarf group) in 25 patients. Indication for the Scarf or Austin technique was made according to the consensus of the Austrian society of foot and ankle surgery. Plantar pressure analysis was performed at 4 weeks, 8 weeks, and 6 months postoperatively. Furthermore, range of motion and the American Orthopaedic Foot and Ankle Society (AOFAS) questionnaire were evaluated. RESULTS: In the big toe and first metatarsal head region in groups, maximum force, peak pressure, and force-time integral increased significantly from 4 weeks to 6 months postoperatively (P ≤ 0.001). The mean AOFAS score increased from 60.7 preoperatively to 93.1 6 months after Austin surgery and from 56.7 preoperatively to 94.4 6 months after Scarf surgery. The Austin group had a mean range of motion (ROM) of 68.5° that increased to a mean ROM of 75.5° 6 months postoperatively, while the Scarf group had a mean ROM of 67.8° that increased to a mean ROM of 68.2° 6 months postoperatively. CONCLUSION: Despite different surgical techniques and the degree of deformity, there were no differences in plantar pressure parameters and functional outcomes between both groups.

Accessibility of the Talar Dome-Anatomic Comparison of Plantarflexion Versus Noninvasive Distraction in Arthroscopy.

PURPOSE: The purpose of this study was to evaluate the difference in accessibility of the talar dome during ankle arthroscopy between noninvasive distraction and maximum plantar flexion without distraction. METHODS: For this study, 20 matched pairs (n = 40) of anatomic ankle specimens were used. Two groups (distraction or maximum plantar flexion) were defined. Through the use of chondral picks, the accessibility of each technique was tested arthroscopically. Afterward, the ankle joint was dissected and the reach achieved was measured and compared between the 2 groups. RESULTS: Through noninvasive distraction, 13.1 ± 4.4 mm of the talar dome was reached laterally and 16.7 ± 3.7 mm medially. Through plantar flexion, 18.1 ± 3.4 mm of the talar dome was reached laterally and 18.1 ± 3.4 mm medially. Statistical comparison revealed a significantly better reach in plantar flexion on the lateral side of the talar dome (P = .007). There was no significant difference medially. CONCLUSIONS: Plantar flexion significantly improves reachability of the dome on the lateral side and it is equal to noninvasive distraction medially. Results of this study may allow for better access to the lesion of the talus. CLINICAL RELEVANCE: Results of this study allow for a better planning of interventions in OCD of the talus.

Preoperative MRI is helpful but not sufficient to detect associated lesions in patients with chronic ankle instability.

PURPOSE: The aim of this study was to determine the reliability and validity of preoperative magnetic resonance imaging (MRI) scans for the detection of additional pathologies in patients with chronic ankle instability (CAI) compared to arthroscopic findings. METHODS: Preoperative MRI images of 30 patients were evaluated regarding articular and periarticular comorbidities and compared to intraoperative findings. The reliability of MRI was determined by calculating specificity, sensitivity, as well as positive and negative predictive values. The accuracy of the classification of cartilage lesions by Outerbridge and Berndt and Harty rating scales was determined by calculating the area under the receiver operating curve (AUC). RESULTS: In total, 72 additional pathologies were found arthroscopically compared to 73 lesions gathered from MRI images. Sensitivity ranged from 89% for peroneal tendinopathy to 28% for additional ligamentous lesions. Specificity ranged from 100% for anterolateral impingement, loose bodies and peroneal tendinopathy to 38% for additional ligamentous lesions. For cartilage lesions, sensitivity was at 91% and specificity was at 55% for the Outerbridge grading scale. For the Berndt and Harty classification system, sensitivity was at 91% and specificity was at 28%. Correlation of additional pathologies ranged from weak (r s = 0.48; p = 0.02) to moderate results (r s = 0.67; p < 0.001). CONCLUSION: CAI is associated with a high incidence of additional pathologies. In some cases, MRI delivers insufficient results, which may lead to misinterpretation of present comorbidities. MRI is a helpful tool for preoperative evaluation, but arthroscopy remains gold standard in the diagnosis of associated lesions in patients with CAI. LEVEL OF EVIDENCE: III.

Anatomical Footprint of the Tibialis Anterior Tendon: Surgical Implications for Foot and Ankle Reconstructions.

This study aimed to analyze precisely the dimensions, shapes, and variations of the insertional footprints of the tibialis anterior tendon (TAT) at the medial cuneiform (MC) and first metatarsal (MT1) base. Forty-one formalin-fixed human cadaveric specimens were dissected. After preparation of the TAT footprint, standardized photographs were made and the following parameters were evaluated: the footprint length, width, area of insertion, dorsoplantar location, shape, and additional tendon slips. Twenty feet (48.8%) showed an equal insertion at the MC and MT1, another 20 feet (48.8%) had a wide insertion at the MC and a narrow insertion at the MT1, and 1 foot (2.4%) demonstrated a narrow insertion at the MC and a wide insertion at the MT1. Additional tendon slips inserting at the metatarsal shaft were found in two feet (4.8%). Regarding the dorsoplantar orientation, the footprints were located medial in 29 feet (70.7%) and medioplantar in 12 feet (29.3%). The most common shape at the MT1 base was the crescent type (75.6%) and the oval type at the MC (58.5%). The present study provided more detailed data on the dimensions and morphologic types of the tibialis anterior tendon footprint. The established anatomical data may allow for a safer surgical preparation and a more anatomical reconstruction.

Bioabsorbable Fixation Screw for Proximal Interphalangeal Arthrodesis of Lesser Toe Deformities.

BACKGROUND: Although standard fixation of proximal interphalangeal (PIP) arthrodesis by K-wire is relatively inexpensive and well established, it does have some drawbacks, making newer fixation devices interesting. The aim of this study was to clinically and radiologically assess the operative correction of the lesser toe deformation in the form of a PIP arthrodesis using a bioabsorbable 2.7-mm fixation screw. METHODS: From January 2011 until October 2013, 34 patients underwent a PIP arthrodesis using the TRIM-IT (Arthrex) 2.7-mm fixation screw and were contacted for this retrospective cohort study. At an average of 3.3 years after the operation, 24 patients and 26 toes were evaluated clinically, radiologically, through pedobarography, and a patient-satisfaction survey. RESULTS: Using the PLLA screw for fixation, 84.6% showed bony union of the arthrodesis, and 84.6% were satisfied. Mean AOFAS score was 82.7 points and thus regarded as good. The mean VAS score was 1.3/10. Overall, 73.1% of the toes showed good alignment, and 7.7% had a painless recurrence of deformity and were still satisfied with the intervention. In addition, 34.6% had floating toes, but only 4.2% without Weil osteotomy or encroachment. Further, 3.8% were advised to undergo a revision because of severe misalignment. CONCLUSION: The 2.7-mm bioabsorbable fixation screw yielded results that were comparable to other fixation devices for PIP fusion fixation regarding success rate, revisions, and patient acceptance. LEVEL OF EVIDENCE: Level IV, retrospective case series.