Ten-year revision rates of contemporary total ankle arthroplasties equal 22%. A meta-analysis.

BACKGROUND: The National Institute for Health and Care Excellence criterion for hip replacements is a (projected) revision rate of less than 5% after 10 years. No such criterion is available for ankle prostheses. The objective of the current study is to compare survival rates of contemporary primary ankle prostheses to the hip-benchmark. METHODS: The PRISMA methodology was used. Eligible for inclusion were clinical studies reporting revision rates of currently available primary total ankle prostheses. Data was extracted using preconstructed forms. The total and prosthesis-specific annual revision rate was calculated. RESULTS: Fifty-seven articles of eight different ankle prostheses were included (n = 5371), totaling 513 revisions at an average 4.6 years of follow-up. An annual revision rate of 2.2 was found (i.e. an expected revision rate of 22% at 10 years). CONCLUSIONS: The expected 10-year revision rate of contemporary ankle prostheses is lower than the current benchmark for hip prostheses.

Return to preinjury sports after anterior cruciate ligament reconstruction is predicted by five independent factors.

PURPOSE: To determine factors that predict return to the same frequency and type of sports participation with similar activity demands as before injury. METHODS: Individuals 1 to 5 years after primary ACL reconstruction completed a comprehensive survey related to sports participation and activity before injury and after surgery. Patient characteristics, injury variables, and surgical variables were extracted from the medical record. Return to preinjury sports (RTPS) was defined as: "Returning to the same or more demanding type of sports participation, at the same or greater frequency with the same or better Marx Activity Score as before injury." Variables were compared between individuals that achieved comprehensive RTPS and those that did not with univariate and multivariate logistic regression models. RESULTS: Two-hundred and fifty-one patients (mean age 26.1 years, SD 9.9) completed the survey at an average of 3.4 years (SD 1.3) after ACL reconstruction. The overall rate of RTPS was 48.6%. Patients were more likely to RTPS if they were younger than 19 years old (OR = 4.07; 95%CI 2.21-7.50; p < 0.01) or if they were competitive athletes (OR = 2.07; 95%CI 1.24-3.46; p = 0.01). Patients were less likely to RTPS if surgery occurred more than 3 months after injury (OR = 0.31, 95%CI 0.17-0.58; p < 0.01), if there was a concomitant cartilage lesion (OR = 0.38; 95%CI 0.21-0.70; p < 0.01), and if cartilage surgery was performed (OR = 0.17; 95%CI 0.04-0.80; p = 0.02). CONCLUSION: Five variables best predicted RTPS including age at time of surgery. Only time from injury to surgery is a potentially modifiable factor to improve RTPS; however, the reasons for which patients delayed surgery may also contribute to them not returning to sports. Regardless, younger patients, those that partake in sports on a competitive level, those that undergo surgery sooner, or do not have a cartilage injury or require cartilage surgery are more likely to return to pre-injury sports participation. LEVEL OF EVIDENCE: III.

Open Versus Endoscopic Surgical Treatment of Posterior Ankle Impingement: A Meta-analysis.

BACKGROUND: Surgical treatment of symptomatic posterior ankle impingement consists of resection of the bony impediment and/or debridement of soft tissue. Historically, open techniques were used to perform surgery with good results. However, since the introduction of endoscopic techniques, advantages attributed to these techniques are shorter recovery time, fewer complications, and less pain. PURPOSE: The primary purpose was to determine whether endoscopic surgery for posterior ankle impingement was superior to open surgery in terms of functional outcome (American Orthopaedic Foot & Ankle Society [AOFAS] score). The secondary aim was to determine differences in return to full activity, patient satisfaction, and complications. STUDY DESIGN: Systematic review and meta-analysis. METHODS: MEDLINE, EMBASE (Classic), and CINAHL databases were searched. Publication characteristics, patient characteristics, surgical techniques, AOFAS scores, time to return to full activity, patient satisfaction, and complication rates were extracted. The AOFAS score was the primary outcome measure. Data were synthesized, and continuous outcome measures (postoperative AOFAS score and time to return to full activity) were pooled using a random-effects inverse variance method. Random-effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients who were satisfied and who experienced complications. RESULTS: A total of 32 studies were included in this review. No statistically significant difference was found in postoperative AOFAS scores between open surgery (88.0; 95% CI, 82.1-94.4) and endoscopic surgery (94.4; 95% CI, 93.1-95.7). There was no difference in the proportion of patients who rated their satisfaction as good or excellent, 0.91 (95% CI, 0.86-0.96) versus 0.86 (95% CI, 0.79-0.94), respectively. No significant difference in time to return to activity was found, 10.8 weeks (95% CI, 7.4-15.9 weeks) versus 8.9 weeks (95% CI, 7.6-10.4 weeks), respectively. Pooled proportions of patients with postoperative complications were 0.15 (95% CI, 0.11-0.19) for open surgery versus 0.08 (95% CI, 0.05-0.14) for endoscopic surgery. Without the poor-quality studies, this difference was statistically significant for both total and minor complications, 0.24 (95% CI, 0.14-0.35) versus 0.02 (95% CI, 0.00-0.06) and 0.14 (95% CI, 0.09-0.20) versus 0.03 (95% CI, 0.01-0.05), respectively. CONCLUSION: We found no statistically significant difference in postoperative AOFAS scores, patient satisfaction, and return to preinjury level of activity between open and endoscopic techniques. The proportion of patients who experienced a minor complication was significantly lower with endoscopic treatment when studies of poor methodological quality were excluded.

Development of a medical device compatible with MRI/CT to measure ankle joint laxity: the Porto Ankle Testing Device.

Ankle sprains are common and often develop into chronic ankle instability. Ankle laxity is usually assessed by manual testing followed by magnetic resonance imaging to confirm the diagnosis. Manual testing however provides a subjective measure and is limited to the assessor sensibility. Current available technologies incorporate arthrometers to objectively measuring ankle laxity, but are not capable to assess the structural integrity of the capsuloligamentous structures. To overcome these limitations, we developed a novel medical device to assist in the diagnosis of ankle ligament injuries-the Porto Ankle Testing Device. With this device, it is possible to combine and correlate the assessment of the capsuloligamentous' structural integrity with the joint functional competence (ie, joint multiplanar laxity). The main purpose of this work is to present the fundamental aspects and step-by-step development of the Porto Ankle Testing Device. We discuss the design specifications and technical requirements with the purpose to design and develop this medical device, described the features of the different components and explained the mechanical systems that are incorporated emulate manual testing and to measure the multiplanar ankle laxity. The preliminary findings are presented with the purpose to display the assessment protocol, the method of laxity measurement and the obtained results. We propose a unique and reliable medical device to safety and effectively assess ankle ligament injuries and contribute to enhance diagnosis, refine treatment indications and allow objective measurement of ligament laxity before and/or after stabilization surgery.

Geometrical characteristics of the symptomatic and non-symptomatic ossa trigona.

BACKGROUND: Posterior ankle impingement is strongly associated with the presence of an os trigonum, however, most patients with an os trigonum will never develop symptoms. It is hypothesized that the os trigonum is larger in the symptomatic ankle than in the non-symptomatic ankle, the distance between os trigonum and tibia is smaller and there are more degenerative changes in ankles with symptoms of posterior impingement. In this study the geometrical characteristics of the ipsilateral and contralateral os trigonum are compared in patients with a bilateral os trigonum and unilateral posterior impingement symptoms. METHODS: Patients with a bilateral os trigonum and unilateral posterior impingement complaints were included. Comparison between the symptomatic and asymptomatic ankles was done within each patient. From the CT-scan of each ankle, the tibia, fibula, calcaneus, talus and os trigonum were segmented and a geometric model was created. Based on these bone models, the volume of the os trigonum and talus, the size of the os trigonum, the distance between os trigonum and surrounding bones (talus, calcaneus, fibula and tibia) were calculated. In addition, the CT images were assessed for the type of os trigonum, the presence of cysts, irregular synchondrosis, calcifications and whether the os trigonum consisted of more than one fragment. RESULTS: A total of 22 patients were included in this study. In seventeen of the 22 patients, the symptomatic os trigonum was larger in comparison with the non-symptomatic side in terms of length (median Δ 2.4 mm, 8.9 versus 10.6 mm) and relative volume (median Δ 0.09%, 0.30 versus 0.45% of talar volume). Distances between the ossa trigona and surrounding bones were not statistically significantly different between both sides. Calcifications were more frequently found around the os trigonum in the symptomatic side (10 versus 3/22). CONCLUSIONS: The findings in this study support the hypothesis that symptomatic ossa trigona are larger in comparison with asymptomatic ossa trigona. Calcifications around the os trigonum were found more frequently in symptomatic than in non-symptomatic ossa trigona. LEVEL OF EVIDENCE: III.

High patient satisfaction and good long-term functional outcome after endoscopic calcaneoplasty in patients with retrocalcaneal bursitis.

PURPOSE: The primary objective of this study was to determine the degree of patient satisfaction at a minimum of 5 years of follow-up after endoscopic calcaneoplasty. The secondary objectives were to assess functional outcome measures, pain scores, analysis of bone removal, reformation of exostosis at follow-up and correlation of the size of the exostosis and recurrent or persisting complaints. METHODS: This study evaluated patients who underwent endoscopic calcaneoplasty, between January 1st 2000 and December 31st 2010, for the diagnosis of retrocalcaneal bursitis. The evaluation consisted of PROMs (patient-reported outcome measures), a questionnaire and a visit to the outpatient clinic for physical examination and a standard lateral weight-bearing radiograph of the ankle. Patient satisfaction, functional outcomes and pain scores were measured by use of a numeric rating scale (NRS). Size of the posterosuperior calcaneal exostosis was measured on a standard lateral weight-bearing radiograph using parallel pitch lines (PPL) and the Fowler-Philip angle (PFA). RESULTS: The response rate was 28 out of 55 (51%) and the median time to follow-up was 101(IQR 88.5-131.8) months. The median satisfaction score for treatment results was 8.5 out of 10 (IQR 6-10). FAOS symptoms 84.5 (IQR 58.0-96.4), FAOS pain 90.3 (IQR 45.1-100.0), FAOS ADL 94.9 (IQR 58.1-100.0), FAOS sport 90.0 (IQR 36.3-100.0) and FAOS QOL 71.9 (IQR 37.5-93.8) and median AOFAS was 100 (IQR 89-100). The median PLL difference between before operation and 2 weeks after the operation was - 4 mm (IQR-6 and -1) and the median PLL difference between 2 weeks after the operation and at follow-up was 1 mm (0-2). The median PFA was 65 (63-69) at baseline, 66.5 (60.8-70.3) 2 weeks after the operation and 64 (60.8-65.3) at follow-up. CONCLUSION: Despite the limited response rate, this study shows high patient satisfaction and good long-term functional outcome in patients affected by retrocalcaneal bursitis who underwent endoscopic calcaneoplasty. LEVEL OF EVIDENCE: Level IV.

Surgical treatment for posteromedial talar process fractures.

PURPOSE: The first descriptions on medial talar tubercle fractures are attributed to Cedell. He described avulsion fractures of the insertion of the posterior talotibial ligament. However the true etiology has not been established. Since little is known about these fractures, they are easily misdiagnosed as simple ankle sprains. Untreated, these fractures may lead to chronic ankle pain. To improve the understanding of the etiology and outcome of these fractures a systematic review was conducted of all cases of isolated fractures of the medial tubercle of the posterior talar process. In addition we present the first series of competitive athletes treated by means of the two-portal hindfoot approach for isolated medial talar tubercle fractures. METHODS: A systematic search was performed to identify all cases of medial tubercle fractures. Data on trauma mechanism, clinical presentation, imaging and treatment were extracted. In addition we retrospectively report on the results of endoscopically treated patients in our institution over the last fifteen years. Of all patients Numeric Rating Scores (NRS) for Satisfaction, Pain and Function, Foot Ankle Outcome Scores (FAOS), return to sport and complications were reported. RESULTS: Eightteen articles were included reporting on 33 patients with an isolated fracture or avulsion of the posteromedial talar process. Most of the fractures occurred during sport activities (58%), followed by motor vehicle accidents (21%) and fall from height (12%). Of the activities during sport, 73% resulted following an ankle sprain. Reasonable to good outcomes are described in cases treated with immobilization, open reduction internal fixation or open excision. Of the nine patients treated in our institution, five were male and the median age was 29. All were participating in sports at a competitive level, with four of them being a professional athlete. In most patients the diagnosis was made more than a year after initial trauma. Ankle sprain was most common trauma mechanism. In some patients it was evident the avulsion was part or the deep portion of the deltoid ligament, however in two cases it was more likely an avulsion of the flexor hallucis longus (FHL) retinaculum. The median follow-up was 69 months (IQR 12.0-94.3). At final follow-up patients had little pain, NRS 1. Median NRS for satisfaction and function were 7 and 8, respectively. All patients did resume sport activities, however only four reached the preinjury level. Of the five patients that did not return to their pre-injury level of activity, two were professional athletes at the end of their career, and retired not due to ankle complaints. One complication was reported. CONCLUSION: Fractures of the medial tubercle are rare and based on the available literature there is not one distinct trauma mechanism. Based on literature no recommendation for treatment can be made. Our results show endoscopic excision of the fragment as a save alternative for open surgical treatment.

The arthroscopic syndesmotic assessment tool can differentiate between stable and unstable ankle syndesmoses.

PURPOSE: Patients with stable isolated injuries of the ankle syndesmosis can be treated conservatively, while unstable injuries require surgical stabilisation. Although evaluating syndesmotic injuries using ankle arthroscopy is becoming more popular, differentiating between stable and unstable syndesmoses remains a topic of on-going debate in the current literature. The purpose of this study was to quantify the degree of displacement of the ankle syndesmosis using arthroscopic measurements. The hypothesis was that ankle arthroscopy by measuring multiplanar fibular motion can determine syndesmotic instability. METHODS: Arthroscopic assessment of the ankle syndesmosis was performed on 22 fresh above knee cadaveric specimens, first with all syndesmotic and ankle ligaments intact and subsequently with sequential sectioning of the anterior inferior tibiofibular ligament, the interosseous ligament, the posterior inferior tibiofibular ligament, and deltoid ligaments. In all scenarios, four loading conditions were considered under 100N of direct force: (1) unstressed, (2) a lateral hook test, (3) anterior to posterior (AP) translation test, and (4) posterior to anterior (PA) translation test. Anterior and posterior coronal plane tibiofibular translation, as well as AP and PA sagittal plane translation, were arthroscopically measured. RESULTS: As additional ligaments of the syndesmosis were transected, all arthroscopic multiplanar translation measurements increased (p values ranging from p < 0.001 to p = 0.007). The following equation of multiplanar fibular motion relative to the tibia measured in millimeters: 0.76*AP sagittal translation + 0.82*PA sagittal translation + 1.17*anterior third coronal plane translation-0.20*posterior third coronal plane translation, referred to as the Arthroscopic Syndesmotic Assessment tool, was generated from our data. According to our results, an Arthroscopic Syndesmotic Assessment value equal or greater than 3.1 mm indicated an unstable syndesmosis. CONCLUSIONS: This tool provides a more reliable opportunity in determining the presence of syndesmotic instability and can help providers decide whether syndesmosis injuries should be treated conservatively or operatively stabilized. The long-term usefulness of the tool will rest on whether an unstable syndesmosis correlates with acute or chronic clinical symptoms.

The calcaneofibular ligament has distinct anatomic morphological variants: an anatomical cadaveric study.

PURPOSE: The purpose of this study was to investigate if the calcaneofibular ligament (CFL) presents morphologic variants and measure the morphometrics of the ligament and its footprints METHODS: An anatomical study of 47 fresh-frozen below-the-knee ankle specimens was performed. Lateral ankle structures were dissected to expose the CFL. Overdissection was avoided to not modify the native morphology. The morphology (number and orientation of CFL bundles) and measurements of CFL insertions were recorded with ankle secured in neutral position. RESULTS: Four distinct morphological-oriented shapes of the CFL were observed. These included single bundle, Y-shape double bundle, V-shape double bundle, and associated with the lateral talocalcaneal ligament. The most frequent CFL morphology observed was the single bundle and the Y-shape double bundle, present in 21 (44.7%) and 13 (27.7%) ankles. The V-shape double bundle and the CFL double bundle associated with the lateral talocalcaneal ligaments were less common, appearing only in eight (17.0%) and five (10.6%) ankles. The CFL length was higher in single bundle and Y-shaped double bundle CFL variants, about 30 mm each. Footprint morphometrics were heterogenous amongst the different CFL variants. CONCLUSION: The CFL presents four distinct morphological-oriented shapes. The double bundle, V-shaped and Y-shaped CFL variants are uncommon and poorly reported in the literature. Their relation to the lateral talocalcaneal ligament and the inferior fascicle of the anterior talofibular ligament requires further research. The CFL morphology provides detailed knowledge of CFL anatomy that can improve diagnostic procedures. Furthermore, this information can fine-tune graft selection and sizing and allow a more precise anatomic placement during surgical reconstruction.

Correction to: The ESSKA-AFAS international consensus statement on peroneal tendon pathologies.

Unfortunately, the spelling of the names Daniel Haverkamp and Ákos Kynsburg were incorrect in the original online publication of the article.

The ESSKA-AFAS international consensus statement on peroneal tendon pathologies.

INTRODUCTION: Peroneal tendon injuries are a significant cause of lateral ankle symptoms in the active population. Accurate diagnosis and prompt treatment is important for minimizing the risk of long-term sequelae associated with chronic peroneal tendinopathy. Although several studies have been published on diagnostic strategies and treatment outcomes, there is no consensus on the optimal management of peroneal tendon pathologies. PURPOSE: The purpose of this ESSKA-AFAS consensus statement was to conduct an international and multidisciplinary agreed guideline on management of patients with peroneal tendon pathologies. METHODS: Using the Nominal Group Technique, a panel comprised of sixteen specialists spanning nine countries was convened by the ESSKA-AFAS board. In preparation for the meeting, relevant questions were identified and supported by a systematic literature search. During the meeting, the panel members gave presentations on each question, and the evidence supporting each subject was then vetted by open discussion. Statements were thereafter adjusted on the basis of the discussion and voted upon to determine consensus using a 0-10 range Likert scale. Agreement was confirmed when a mean score of at least 7.5 was reached. CONCLUSION: This ESSKA-AFAS consensus statement on the optimal management of peroneal tendon pathologies is the result of international and multidisciplinary agreement combined with a systematic review of the literature. LEVEL OF EVIDENCE: V.

Metal Resurfacing Inlay Implant for Osteochondral Talar Defects After Failed Previous Surgery: A Midterm Prospective Follow-up Study.

BACKGROUND: Treatment of osteochondral talar defects (OCDs) after failed previous surgery is challenging. Promising short-term results have been reported with use of a metal resurfacing inlay implant. PURPOSE: To evaluate the midterm clinical effectiveness of the metal implant for OCDs of the medial talar dome after failed previous surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We prospectively studied all patients who met the inclusion criteria and received a metal resurfacing inlay implant between 2007 and 2014. The primary outcome measure was implant survival, as measured by reoperation rate. Secondary outcome measures were numeric rating scales for pain at rest and during walking, running, and stair climbing; the Foot and Ankle Outcome Score (FAOS); the American Orthopaedic Foot and Ankle Society Ankle Hindfoot Scale; the 36-Item Short Form Health Survey (SF-36); return to work and sports; and radiographic evaluation. RESULTS: This study included 38 patients with a mean age of 39 years (SD, ±13 years) and a mean follow-up of 5.1 years (SD, ±1.5 years). Two patients (5%) underwent revision surgery by means of an ankle arthrodesis (2 and 6 years postoperatively). In 8 patients, computed tomography scanning was conducted to assess postoperative complaints. These scans showed impression of the tibial plafond (n = 4), a small tibial cyst (<2.5 mm; n = 1), and cyst formation around the implant screw (n = 4). A total of 21 reoperations were performed, including medial malleolar screw removal (n = 12), arthroscopic removal of bony anterior impingement (n = 7), and calcaneal realignment osteotomy (n = 2). All secondary outcome measures improved significantly, apart from pain at rest, the FAOS symptoms subscale, and the SF-36 mental component scale. The mean time for return to sport was 4.1 months (SD, ±3 months), and 77% of patients resumed sporting activities postoperatively. Only 1 patient did not return to work postoperatively. Radiographs at final follow-up showed cyst formation (n = 2), subchondral periprosthetic radiolucency (n = 2), and non-preexisting joint space narrowing (n = 2). CONCLUSION: This study shows that the metal implant is an effective technique when assessed at midterm follow-up for OCDs of the medial talar dome after failed previous surgery.

Diagnosis, treatment and prevention of ankle sprains: update of an evidence-based clinical guideline.

This guideline aimed to advance current understandings regarding the diagnosis, prevention and therapeutic interventions for ankle sprains by updating the existing guideline and incorporate new research. A secondary objective was to provide an update related to the cost-effectiveness of diagnostic procedures, therapeutic interventions and prevention strategies. It was posited that subsequent interaction of clinicians with this guideline could help reduce health impairments and patient burden associated with this prevalent musculoskeletal injury. The previous guideline provided evidence that the severity of ligament damage can be assessed most reliably by delayed physical examination (4-5 days post trauma). After correct diagnosis, it can be stated that even though a short time of immobilisation may be helpful in relieving pain and swelling, the patient with an acute lateral ankle ligament rupture benefits most from use of tape or a brace in combination with an exercise programme.New in this update: Participation in certain sports is associated with a heightened risk of sustaining a lateral ankle sprain. Care should be taken with non-steroidal anti-inflammatory drugs (NSAIDs) usage after an ankle sprain. They may be used to reduce pain and swelling, but usage is not without complications and NSAIDs may suppress the natural healing process. Concerning treatment, supervised exercise-based programmes preferred over passive modalities as it stimulates the recovery of functional joint stability. Surgery should be reserved for cases that do not respond to thorough and comprehensive exercise-based treatment. For the prevention of recurrent lateral ankle sprains, ankle braces should be considered as an efficacious option.

Endoscopic Treatment of Mid-Portion Achilles Tendinopathy: A Retrospective Case Series of Patient Satisfaction and Functional Outcome at a 2- to 8-Year Follow-up.

PURPOSE: To evaluate the results of endoscopic treatment in patients affected by mid-portion Achilles tendinopathy, by release of the paratenon combined with a resection of the plantaris tendon, regarding patient satisfaction, functional outcome, and pain scores. METHODS: This retrospective study evaluated patients endoscopically treated for mid-portion Achilles tendinopathy between 2000 and 2013. Patient satisfaction, functional outcome, pain scores, and health-related quality of life were measured by the use of a numeric rating scale, the Foot and Ankle Outcome Score, the Victorian Institute of Sport assessment for the Achilles tendon, the numeric rating scale for pain during running and during sports, and the EuroQol 5D (EQ-5D-3L) standardized questionnaire. Additional questions were asked on the effectiveness of the treatment and sport participation. RESULTS: The response rate was 76.3% (45 of 59). Thirty-five (78%) patients were treated unilaterally and 10 (22%) patients were treated bilaterally. For the unilaterally treated patients, the median time to follow-up was 67 months (interquartile range [IQR] 48-99 months), and for the bilaterally treated patients, it was 89.5 months (IQR 37.5-161.75 months). The median satisfaction score for treatment results was 9 out of 10 (IQR 7-10) and 9.5 (IQR 7-10), respectively. The median Foot and Ankle Outcome Score subscales were scored 75 to 99 and 75 to 97, the median Victorian Institute of Sport assessment for the Achilles tendon scored 81 (IQR 47-90) and 97 (IQR 87-100), and the median numeric rating scale pain scores during both running and sports were 1 (IQR 0-6.5) for the unilaterally treated patients and 0 (IQR 0-4.5) and 0 (IQR 0-1) for the bilaterally treated patients, respectively. The median EQ-5D were 0.81 (IQR 0.71-1) and 1 (IQR 0.64-1), respectively. One reoperation for recurrence of symptoms was necessary. CONCLUSIONS: This study shows high patient satisfaction and good functional outcomes in patients affected by mid-portion Achilles tendinopathy who were endoscopically treated by means of release of the paratenon in combination with transection of the plantaris tendon. LEVEL OF EVIDENCE: Level IV, retrospective case series (therapeutic).

The Cumberland Ankle Instability Tool (CAIT) in the Dutch population with and without complaints of ankle instability.

PURPOSE: To develop a translated Dutch version of the Cumberland Ankle Instability Tool (CAIT) and test its psychometric properties in a Dutch population with foot and ankle complaints. METHODS: The CAIT was translated into the Dutch language using a forward-backward translation design. Of the 130 subsequent patients visiting the outpatient clinic for foot and ankle complaints who were asked to fill out a questionnaire containing the CAIT, the Foot and Ankle Outcome Score (FAOS), and the numeric rating scale (NRS) pain, 98 completed the questionnaire. After a 1-week period, patients were asked to fill out a second questionnaire online containing the CAIT and NRS pain. This second questionnaire was completed by 70 patients. With these data, the construct validity, test-retest reliability, internal consistency, measurement error, and ceiling and floor effects were assessed. Additionally, a cut-off value to discriminate between stable and unstable ankles, in patients with ankle complaints, was calculated. RESULTS: Construct validity showed moderate correlations between the CAIT and FAOS subscales (Spearman's correlation coefficient (SCC) = 0.36-0.43), and the NRS pain (SCC = -0.55). The cut-off value was found at 11.5 points of the total CAIT score (range 0-30). Test-retest reliability showed to be excellent with an intraclass correlation coefficient of 0.94. Internal consistency was high (Cronbach's α = 0.86). No ceiling or floor effects were detected. CONCLUSION: Based on the results, the Dutch version of the CAIT is a valid and reliable questionnaire to assess ankle instability in the Dutch population and is able to differentiate between a functionally unstable and stable ankle. The tool is the first suitable tool to objectify the severity of ankle instability specific complaints and assess change in the Dutch population. Level of evidence II.

Prevalence of Os Trigonum on CT Imaging.

BACKGROUND: The os trigonum is known as one of the main causes of posterior ankle impingement. In the literature, a wide variation of occurrence has been reported. METHODS: All foot and/or ankle computed tomography (CT) scans made between January 2012 and December 2013 were reviewed. CT images were assessed, blinded for patient characteristics, for the presence of an os trigonum, size of the os trigonum, and type of os trigonum. In addition, the shape of the lateral tubercle of the posterior talar process was assessed. RESULTS: A total of 628 patients (1256 ankles) were included. In 32.5% of the patients of the cohort, an os trigonum was present. In 14.3% of these patients, it was present bilaterally. In a subgroup of patients without posterior ankle impingement the prevalence was 30.3%. Of the nonaffected ankles, an os trigonum was present in 23.7%. Patients with posterior ankle impingement were more likely to have an os trigonum (adjusted odds ratio [OR], 1.86). Afro-Caribbean/Surinamese/Central African origin was associated with a lower rate of occurrence of os trigonum (adjusted OR 0.43). In the ankles without an os trigonum, an enlarged lateral tubercle of the posterior talar process was found in 34.9% and 36.5% of the ankles. CONCLUSION: This study showed that os trigonum is a common accessory bone. With a prevalence of 30.3% in a population of patients with CT imaging of both ankles and 23.7% of the nonaffected ankles, the os trigonum is more common than previously reported. Patients with posterior ankle impingement complaints had a higher prevalence of an os trigonum. In one-third of the patients without an os trigonum, there was an enlarged lateral tubercle of the posterior talar process. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

The Rate of Radial Head Prosthesis Removal or Revision: A Systematic Review and Meta-Analysis.

PURPOSE: We conducted a meta-analysis and systematic review with the primary objective to determine the overall incidence of radial head prosthesis removal or revision. Our secondary objectives addressed the incidence of removal or revision based on the type of prosthesis fixation (cemented, uncemented smooth stem, uncemented press-fit), material (metal, Vitallium, titanium, pyrocarbon), and design (short vs long stem and monopolar vs bipolar), and the reasons for prosthetic removal or revision. METHODS: We included 30 studies with a total of 1,017 patients out of whom 77 prostheses were removed and 45 prostheses were revised. RESULTS: The pooled rate of radial head prosthesis removal or revision was 10.0% (95% confidence interval, 7.3%-13.6%) with a mean follow-up of 38 months. Subgroup analysis showed that the incidence of removal/revision was lowest with the cemented fixation, longer-stem, Vitallium material, and bipolar prosthesis. More than half of the prostheses were removed/revised for excision of the heterotopic ossification (47%) and for the treatment of stiffness and limitation of motion (42%). Other reasons recorded were pain (19%), loosening (16%), overstuffing (13%), instability (12%), infection (8%), and prosthesis disassembly (4%). CONCLUSIONS: The current data show that the highest incidence of removal/revision occurred within 2 years after implantation. There was no major difference in the incidence of removal/revision among different designs and materials. Implant removal was often performed as part of a procedure to manage elbow stiffness and heterotopic ossification at the surgeon's preference, not necessarily because the implant was malfunctioning. It appears that most radial head arthroplasties have an acceptable and comparable mid-term longevity; however, it is unclear whether long-term longevity will differ between devices. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Predicting pathological fracture in femoral metastases using a clinical CT scan based algorithm: A case-control study.

BACKGROUND: We assessed whether there was a difference in attenuation measurements (in Hounsfield units - HU) and geometric distribution of HU between femora with metastatic lesions that fracture, and metastatic lesions that did not fracture nor underwent prophylactic fixation. METHODS: Nine patients with femoral metastases who underwent CT and developed a pathological fracture were matched to controls. All femora were delineated in axial CT slices using a region of interest (ROI) tool; the HU within these ROIs were used to calculate: (1) the cumulative HU of the affected over the nonaffected side per slice and presented as a percentage, and (2) the cumulative HU accounting for geometric distribution (polar moment of HU). We repeated the analyses including cortical bone only (HU of 600 and above). RESULTS: CT-based calculations did not differ between patients with a lesion that fractured and those that did not fracture nor underwent prophylactic fixation when analyzing all tissue. However, when including cortical bone only, the pathological fracture group had a lower cumulative HU value compared to the no fracture and no fixation group for the weakest cross-sectional CT image (pathological fracture group, mean: 71, SD: 23 and no fracture and no prophylactic fixation group, mean: 85, SD: 18, p = 0.042) and the complete lesion analysis (pathological fracture group, mean: 78, SD: 21 and no fracture and no prophylactic fixation group, mean: 92, SD: 15, p = 0.032). CONCLUSION: The demonstrated CT-based algorithms can be useful for predicting pathological fractures in metastatic lesions.