Conventional vs Augmented Reality-Guided Lateral Calcaneal Lengthening Simulated in a Foot Bone Model.

BACKGROUND: Acquired adult flatfoot deformity (AAFD) results in a loss of the medial longitudinal arch of the foot and dysfunction of the posteromedial soft tissues. Hintermann osteotomy (H-O) is often used to treat stage II AAFD. The procedure is challenging because of variations in the subtalar facets and limited intraoperative visibility. We aimed to assess the impact of augmented reality (AR) guidance on surgical accuracy and the facet violation rate. METHODS: Sixty AR-guided and 60 conventional osteotomies were performed on foot bone models. For AR osteotomies, the ideal osteotomy plane was uploaded to a Microsoft HoloLens 1 headset and carried out in strict accordance with the superimposed holographic plane. The conventional osteotomies were performed relying solely on the anatomy of the calcaneal lateral column. The rate and severity of facet joint violation was measured, as well as accuracy of entry and exit points. The results were compared across AR-guided and conventional osteotomies, and between experienced and inexperienced surgeons. RESULTS: Experienced surgeons showed significantly greater accuracy for the osteotomy entry point using AR, with the mean deviation of 1.6 ± 0.9 mm (95% CI 1.26, 1.93) compared to 2.3 ± 1.3 mm (95% CI 1.87, 2.79) in the conventional method (P = .035). The inexperienced had improved accuracy, although not statistically significant (P = .064), with the mean deviation of 2.0 ± 1.5 mm (95% CI 1.47, 2.55) using AR compared with 2.7 ± 1.6 mm (95% CI 2.18, 3.32) in the conventional method. AR helped the experienced surgeons avoid full violation of the posterior facet (P = .011). Inexperienced surgeons had a higher rate of middle and posterior facet injury with both methods (P = .005 and .021). CONCLUSION: Application of AR guidance during H-O was associated with improved accuracy for experienced surgeons, demonstrated by a better accuracy of the osteotomy entry point. More crucially, AR guidance prevented full violation of the posterior facet in the experienced group. Further research is needed to address limitations and test this technology on cadaver feet. Ultimately, the use of AR in surgery has the potential to improve patient and surgeon safety while minimizing radiation exposure. CLINICAL RELEVANCE: Subtalar facet injury during lateral column lengthening osteotomy represents a real problem in clinical orthopaedic practice. Because of limited intraoperative visibility and variable anatomy, it is hard to resolve this issue with conventional means. This study suggests the potential of augmented reality to improve the osteotomy accuracy.

A Smaller Tibiotalar Sector Is a Risk Factor for Recurrent Anterolateral Ankle Instability after a Modified Broström-Gould Procedure.

BACKGROUND: Several demographic and clinical risk factors for recurrent ankle instability have been described. The main objective of this study was to investigate the potential influence of morphologic characteristics of the ankle joint on the occurrence of recurrent instability and the functional outcomes following a modified Broström-Gould procedure for chronic lateral ankle instability. METHODS: Fifty-eight ankles from 58 patients (28 males and 30 females) undergoing a modified Broström-Gould procedure for chronic lateral ankle instability between January 2014 and July 2021 were available for clinical and radiological evaluation. Based on the preoperative radiographs, the following radiographic parameters were measured: talar width (TW), tibial anterior surface (TAS) angle, talar height (TH), talar radius (TR), tibiotalar sector (TTS), and tibial lateral surface (TLS) angle. The history of recurrent ankle instability and the functional outcome using the Karlsson Score were assessed after a minimum follow-up of 2 years. RESULTS: Recurrent ankle instability was reported in 14 patients (24%). The TTS was significantly lower in patients with recurrent ankle instability (69.8 degrees vs 79.3 degrees) (P < .00001). The multivariate logistic regression model confirmed the TTS as an independent risk factor for recurrent ankle instability (OR = 1.64) (P = .003). The receiver operating characteristic curve analysis revealed that patients with a TTS lower than 72 degrees (=low-TTS group) had an 82-fold increased risk for recurrent ankle instability (P = .001). The low-TTS group showed a significantly higher rate of recurrent instability (58% vs 8%; P = .0001) and a significantly lower Karlsson score (65 points vs 85 points; P < .00001). CONCLUSION: A smaller TTS was found to be an independent risk factor for recurrent ankle instability and led to poorer functional outcomes after a modified Broström-Gould procedure. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Ten-Year Minimum Follow-up Study of First Metatarsophalangeal Joint Fusion in Young vs Old Patients.

BACKGROUND: Painful degenerative joint disease (DJD) of the first metatarsophalangeal joint (MTP I), or hallux rigidus, mainly occurs in later stages of life. For end-stage hallux rigidus, MTP I arthrodesis is considered the gold standard. As young and active patients are affected considerably less frequently, it currently remains unclear, whether they benefit to the same extent. We hypothesized that MTP I arthrodesis in younger patients would lead to an inferior outcome with decreased rates of overall with lower rates of patient postoperative pain and function compared to an older cohort. METHODS: All patients aged <50 years who underwent MTP I arthrodesis at our institution between 1995 and 2012 were included in this study. This group was then matched and compared with a group of patients aged >60 years. Minimum follow-up was 10 years. Outcome measures were Tegner activity score (TAS), a "Virtual Tegner activity score" (VTAS), the visual analog scale (VAS), and the Foot Function index (FFI). RESULTS: Sixty-one MTP I fusions (n = 28 young, n = 33 old) in 46 patients were included in our study at an average of 14 years after surgery. Younger patients experienced significantly more pain relief as reflected by changes in VAS and FFI Pain subscale scores. No difference in functional outcomes was found with change in the FFI function subscale or in the ability to have desired functional outcomes using the ratio of TAS to VTAS. Revision rate did not differ between the two groups apart from hardware removal, which was significantly more likely in the younger group. CONCLUSION: In patients below the age of 50 years with end-stage DJD of the first metatarsal joint, MTP I arthrodesis not only yielded highly satisfactory postoperative results at least equal outcome compared to an older cohort of patients aged >60 years at an average 14 years' follow-up. Based on these findings, we consider first metatarsal joint fusion even for young patients is a valid option to treat end-stage hallux rigidus. LEVEL OF EVIDENCE: Level III, a case-control study.

The Unloading Effect of Supramalleolar Versus Sliding Calcaneal Osteotomy for Treatment of Osteochondral Lesions of the Medial Talus: A Biomechanical Study.

Background: In patients with osteochondral lesion, defects of the medial talus, or failed cartilage surgery, a periarticular osteotomy can unload the medial compartment. Purpose: To compare the effects of supramalleolar osteotomy (SMOT) versus sliding calcaneal osteotomy (SCO) for pressure redistribution and unloading of the medial ankle joint in normal, varus-aligned, and valgus-aligned distal tibiae. Study Design: Controlled laboratory study. Methods: Included were 8 cadaveric lower legs with verified neutral ankle alignment (lateral distal tibial angle [LDTA] = 0°) and hindfoot valgus within normal range (0°-10°). SMOT was performed to modify LDTA between 5° valgus, neutral, and 5° varus. In addition, a 10-mm lateral SCO was performed and tested in each position in random order. Axial loading (700 N) of the tibia was applied with the foot in neutral alignment in a customized testing frame. Pressure distribution in the ankle joint and subtalar joint, center of force, and contact area were recorded using high-resolution Tekscan pressure sensors. Results: At neutral tibial alignment, SCO unloaded the medial joint by a mean of 10% ± 10% or 66 ± 51 N (P = .04) compared with 6% ± 12% or 55 ± 72 N with SMOT to 5° valgus (P = .12). The achieved deload was not significantly different (ns) between techniques. In ankles with 5° varus alignment at baseline, SMOT to correct LDTA to neutral insufficiently addressed pressure redistribution and increased medial load by 6% ± 9% or 34 ± 33 N (ns). LDTA correction to 5° valgus (10° SMOT) unloaded the medial joint by 0.4% ± 14% or 20 ± 75 N (ns) compared with 9% ± 11% or 36 ± 45 N with SCO (ns). SCO was significantly superior to 5° SMOT (P = .017) but not 10° SMOT. The subtalar joint was affected by both SCO and SMOT, where SCO unloaded but SMOT loaded the medial side. Conclusion: SCO reliably unloaded the medial compartment of the ankle joint for a neutral tibial axis. Changes in the LDTA by SMOT did not positively affect load distribution, especially in varus alignment. The subtalar joint was affected by SCO and SMOT in opposite ways, which should be considered in the treatment algorithm. Clinical Relevance: SCO may be considered a reliable option for beneficial load-shifting in ankles with neutral alignment or 5° varus malalignment.

[Three-dimensional analysis of posttraumatic tibial shaft malunion and correction based on the healthy, contralateral leg]. / 3-D-Analyse von posttraumatischen Tibiaschaftfehlstellungen und deren Korrektur anhand der gesunden Gegenseite.

OBJECTIVE: Three-dimensional (3D) analysis and implementation with patient-specific cutting and repositioning blocks enables correction of complex tibial malunions. Correction can be planned using the contralateral side or a statistical model. Patient-specific 3D-printed cutting guide blocks enable a precise osteotomy and reduction guide blocks help to achieve anatomical reduction. Depending on the type and extent of correction, fibula osteotomy may need to be considered to achieve the desired reduction. CONTRAINDICATIONS: a) Poor soft tissue (flap surgery, adherent skin in field of operation); b) infection; c) peripheral artery disease (stage III and IV classified according to Fontaine, critical transcutaneous oxygen partial pressure, TcPO2); d) general contraindication to surgery. SURGICAL TECHNIQUE: Before surgery, a 3D model of both lower legs is created based on computed tomography (CT) scans. Analysis of the deformity based on the contralateral side in a 3D computer model (CASPA) and planning of the osteotomy. If the contralateral side also has a deformity, a statistical model can be used. Printing of patient-specific guides made of nylon (PA2200) for the osteotomy and reduction. Surgery is performed in supine position, antibiotic prophylaxis, thigh tourniquet, which is used as needed. Ventrolateral approach to the tibia. Attachment of the patient-specific osteotomy guide, performance of the osteotomy. Reduction using the guide. Fibula osteotomy through a lateral approach is performed if the reduction of the tibia is hindered by the fibula. This can be performed freehand or with patient-specific guides. Wound closure. POSTOPERATIVE MANAGEMENT: Compartment monitoring. Passive mobilization of the ankle in the cast as soon as the wound healing has progressed. Partial weightbearing in a lower leg cast for at least 6-12 weeks, depending on the routinely performed radiographic assessment 6 weeks postoperatively. Thromboprophylaxis with low molecular weight heparin until cast removal. RESULTS: Patient-specific correction of malunions are generally good. This could be confirmed for distal tibial corrections. For tibial shaft deformities, the final results are still pending. Preliminary results, however, show good feasibility with a pseudarthrosis rate of 10% without postoperative infection.

Ulcer occurrence on adjacent toes and hallux valgus deformity after amputation of the second toe in diabetic patients.

BACKGROUND: Amputation of the second toe is associated with destabilization of the first toe. Possible consequences are hallux valgus deformity and subsequent pressure ulcers on the lateral side of the first or on the medial side of the third toe. The aim of this study was to investigate the incidence and possible influencing factors of interdigital ulcer development and hallux valgus deformity after second toe amputation. METHODS: Twenty-four cases of amputation of the second toe between 2004 and 2020 (mean age 68 ± 12 years; 79% males) were included with a mean follow-up of 36 ± 15 months. Ulcer development on the first, third, or fourth toe after amputation, the body mass index (BMI) and the amputation level (toe exarticulation versus transmetatarsal amputation) were recorded. Pre- and postoperative foot radiographs were evaluated for the shape of the first metatarsal head (round, flat, chevron-type), the hallux valgus angle, the first-second intermetatarsal angle, the distal metatarsal articular angle and the hallux valgus interphalangeal angle by two orthopedic surgeons for interobserver reliability. RESULTS: After amputation of the second toe, the interdigital ulcer rate on the adjacent toes was 50% and the postoperative hallux valgus rate was 71%. Neither the presence of hallux valgus deformity itself (r = .19, p = .37), nor the BMI (r = .09, p = .68), the shape of the first metatarsal head (r = - .09, p = .67), or the amputation level (r = .09, p = .69) was significantly correlated with ulcer development. The interobserver reliability of radiographic measurements was high, oscillating between 0.978 (p = .01) and 0.999 (p = .01). CONCLUSIONS: The interdigital ulcer rate on the first or third toe after second toe amputation was 50% and hallux valgus development was high. To date, evidence on influencing factors is lacking and this study could not identify parameters such as the BMI, the shape of the first metatarsal head or the amputation level as risk factors for the development of either hallux valgus deformity or ulcer occurrence after second toe amputation. TRIAL REGISTRATION: BASEC-Nr. 2019-01791.

Effect of the Reversed L-Shaped Osteotomy on the Round Sign: Not All Hallux Valgus Deformities May Need Proximal Derotation to Correct the Radiographic Appearance of Metatarsal Pronation.

Background: Metatarsal pronation has been claimed to be a risk factor for hallux valgus recurrence. A rounded shape of the lateral aspect of the first metatarsal head has been identified as a sign of persistent metatarsal pronation after hallux valgus correction. This study investigated the derotational effect of a reversed L-shaped (ReveL) osteotomy combined with a lateral release to correct metatarsal pronation. The primary hypothesis was that most cases showing a positive round sign are corrected by rebalancing the metatarsal-sesamoid complex. We further assumed that the inability to correct the round sign might be a risk factor for hallux valgus recurrence. Methods: We retrospectively evaluated 266 cases treated with a ReveL osteotomy for hallux valgus deformity. The radiologic measurements were performed on weightbearing foot radiographs preoperatively, at an early follow-up (median, 6.2 weeks), and the most recent follow-up (median, 13 months). Univariate and multivariate logistic regression analyses identified risk factors for hallux valgus recurrence (hallux valgus angle [HVA] ≥ 20 degrees). Results: A preoperative positive radiographic round sign was present in 40.2% of the cases, of which 58.9% turned negative after the ReveL osteotomy (P < .001). Hallux valgus recurred in 8.6%. Risk factors for recurrence were a preoperative HVA >30 degrees (odds ratio [OR] = 5.3, P < .001), metatarsus adductus (OR = 4.0, P = .004), preoperative positive round sign (OR = 3.3, P = .02), postoperative HVA >15 degrees (OR = 74.9; P < .001), and postoperative positive round sign (OR = 5.3, P = .008). Cases with a positive round sign at the most recent follow-up had a significantly higher recurrence rate than those with a negative round sign (22.7% vs 5.9%, P < .001). Conclusion: The ReveL osteotomy corrected a positive round sign in 58.9%, suggesting that not all hallux valgus deformities may need proximal derotation to negate the radiographic appearance of the round sign. A positive round sign was found to be an independent risk factor for hallux valgus recurrence. Further 3-dimensional analyses are necessary to better understand the effects and limitations of distal translational osteotomies to correct metatarsal pronation. Level of Evidence: Level IV, case series.

Outcomes of Tibialis Anterior Tendon Reconstruction with Autograft or Allograft.

BACKGROUND: In cases of tibialis anterior tendon (TAT) ruptures associated with significant tendon defect, an interposition graft is often needed for reconstruction. Both auto- and allograft reconstructions have been described in the literature. Our hypothesis was that both graft types would have a good integrity and provide comparable outcomes. METHODS: Patients who underwent TAT reconstruction using either an auto- or allograft were identified. Patient-reported outcomes (PROs) were collected using the 12-Item Short Form Health Survey (SF-12) questionnaire, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the Foot Function Index (FFI), and the Karlsson-Peterson score. Functional outcome was assessed by isokinetic strength measurement. Outcomes were further assessed with magnetic resonance imaging (MRI) evaluation of graft integrity. All measurements were also performed for the contralateral foot. RESULTS: Twenty-one patients with an average follow-up of 82 months (20-262 months), comprising 12 allograft and 9 autograft TAT reconstructions, were recruited. There were no significant differences in patient-reported outcomes between allograft reconstructions and autografts: SF-12 (30.7 vs 31.1, P = .77); AOFAS (83 vs 91.2, P = .19); FFI (20.7% vs 9.5%, P = .22); and Karlsson-Peterson (78.9 vs 87.1, P = .23). All grafts (100%) were intact on MRI with a well-preserved integrity and no signs of new rupture. There were no major differences in range of motion and functional outcomes as measured by strength testing between the operative and nonoperative side. CONCLUSION: Reconstructions of TAT achieved good PROs, as well as functional and imaging results with a preserved graft integrity in all cases. There were no substantial differences between allograft and autograft reconstructions. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Talus morphology differs between flatfeet and controls, but its variety has no influence on extent of surgical deformity correction.

BACKGROUND: Progressive collapsing foot deformity (PCFD) is a complex 3-dimensional (3-D) deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus. The first aim of this study was to perform a 3-D analysis of the talus morphology between symptomatic PCFD patients that underwent operative flatfoot correction and controls. The second aim was to investigate if there is an impact of individual talus morphology on the success of operative flatfoot correction. METHODS: We reviewed all patients that underwent lateral calcaneal lengthening for correction of PCFD between 2008 and 2018 at our clinic. Radiographic flatfoot parameters on preoperative and postoperative radiographs were assessed. Additionally, 3-D surface models of the tali were generated using computed tomography (CT) data. The talus morphology of 44 flatfeet was compared to 3-D models of 50 controls without foot or ankle pain of any kind. RESULTS: Groups were comparable regarding demographics. Talus morphology differed significantly between PCFD and controls in multiple aspects. There was a 2.6° increased plantar flexion (22.3° versus 26°; p = 0.02) and medial deviation (31.7° and 33.5°; p = 0.04) of the talar head in relation to the body in PCFD patients compared to controls. Moreover, PCFD were characterized by an increased valgus (difference of 4.6°; p = 0.01) alignment of the subtalar joint. Satisfactory correction was achieved in all cases, with an improvement of the talometatarsal-angle and the talonavicular uncoverage angle of 5.6° ± 9.7 (p = 0.02) and 9.9° ± 16.3 (p = 0.001), respectively. No statistically significant correlation was found between talus morphology and the correction achieved or loss of correction one year postoperatively. CONCLUSION: The different morphological features mentioned above might be contributing or risk factors for progression to PCFD. However, despite the variety of talar morphology, which is different compared to controls, the surgical outcome of calcaneal lengthening osteotomy was not affected. LEVEL OF EVIDENCE: III.

Autologous Matrix-Induced Chondrogenesis With Lateral Ligament Stabilization for Osteochondral Lesions of the Talus in Patients With Ankle Instability.

BACKGROUND: Autologous matrix-induced chondrogenesis (AMIC) has been shown to result in favorable clinical outcomes in patients with osteochondral lesions of the talus (OLTs). Though, the influence of ankle instability on cartilage repair of the ankle has yet to be determined. PURPOSE/HYPOTHESIS: To compare the clinical and radiographic outcomes in patients with and without concomitant lateral ligament stabilization (LLS) undergoing AMIC for the treatment of OLT. It was hypothesized that the outcomes would be comparable between these patient groups. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Twenty-six patients (13 with and 13 without concomitant ankle instability) who underwent AMIC with a mean follow-up of 4.2 ± 1.5 years were enrolled in this study. Patients were matched 1:1 according to age, body mass index (BMI), lesion size, and follow-up. Postoperative magnetic resonance imaging and Tegner, American Orthopaedic Foot & Ankle Society (AOFAS), and Cumberland Ankle Instability Tool (CAIT) scores were obtained at a minimum follow-up of 2 years. A musculoskeletal radiologist scored all grafts according to the MOCART (magnetic resonance observation of cartilage repair tissue) 1 and MOCART 2.0 scores. RESULTS: The patients' mean age was 33.4 ± 12.7 years, with a mean BMI of 26.2 ± 3.7. Patients with concomitant LLS showed worse clinical outcome measured by the AOFAS (85.1 ± 14.4 vs 96.3 ± 5.8; P = .034) and Tegner (3.8 ± 1.1 vs 4.4 ± 2.3; P = .012) scores. Postoperative CAIT and AOFAS scores were significantly correlated in patients with concomitant LLS (r = 0.766; P = .002). A CAIT score >24 (no functional ankle instability) resulted in AOFAS scores comparable with scores in patients with isolated AMIC (90.1 ± 11.6 vs 95.3 ± 6.6; P = .442). No difference was seen between groups regarding MOCART 1 and 2.0 scores (P = .714 and P = .371, respectively). CONCLUSION: Concurrently performed AMIC and LLS in patients with OLT and ankle instability resulted in clinical outcomes comparable with isolated AMIC if postoperative ankle stability was achieved. However, residual ankle instability was associated with worse postoperative outcomes, highlighting the need for adequate stabilization of ankle instability in patients with OLT.

Flexor hallucis longus hypertrophy secondary to Achilles tendon tendinopathy: an MRI-based case-control study.

PURPOSE: The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL). METHODS: MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, while the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4-5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cutoff points to differentiate between the groups. RESULTS: A total of 60 patients for each study group were included. Both ratios Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p < 0.001). There were strong to very strong intraclass correlation coefficients (ICC = 0.75-0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy. CONCLUSION: In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

Clinical and Functional Outcomes of Peroneus Longus to Brevis Tendon Transfer.

BACKGROUND: Peroneal tendon lesions can cause debilitating pain, but operative treatment remains controversial. Some studies recommend peroneal tenodesis or transfer if more than half of the tendon is affected. However, clinical outcomes and inversion/eversion motion after peroneal transfer have not been investigated yet. METHODS: Patients who underwent distal peroneus longus to brevis transfer for major peroneus brevis tendon tears with a minimum follow-up of 2 years were included. Clinical outcome parameters included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the German Foot Function Index (FFI-D), and Karlsson-Peterson score. Functional outcome was tested with a standardized active range-of-motion (ROM) and isokinetic strength measurement protocol, including concentric and eccentric eversion and inversion tests. RESULTS: Of total 23 eligible patients, 14 (61%) were available for follow-up. Clinical outcome scores were good with AOFAS 86 ± 16 points, FFI-D pain 26% and FFI-D disability 26%, and Karlsson-Peterson score 78 ± 23 points. There was no difference in strength in comparison to the contralateral foot (all P > .05). Isokinetic strength was 16.3 ± 4.9 Nm (108% of contralateral side) and 18.8 ± 4.5 Nm (101%) at concentric 30 deg/s and eccentric 30 deg/s eversion tests, as well as 15.7 ± 5.2 Nm (102%) and 18.7 ± 3.3 Nm (103%) at concentric 30 deg/s and eccentric 30 deg/s inversion tests, respectively. There was no difference in ROM compared to the contralateral side (eversion/inversion 14.5-0-18.7 vs 14.1-0-16.1 degrees). CONCLUSION: Peroneus longus to brevis transfer is a viable option for treating severe peroneus brevis tendon tears and does not compromise measurable strength or ROM in inversion or eversion in comparison to the contralateral ankle joint. LEVEL OF EVIDENCE: Level IV, prospective case series.

Planning tool for first metatarsal length in hallux valgus surgery.

BACKGROUND: The precise planning of metatarsal (MT) I length in hallux valgus surgery is important. However, currently no tool exists which allows the surgeon to reliably predict this parameter. METHODS: 30 virtual 3-dimensional hallux valgus surgeries were performed on varied deformation models based on cadaveric feet scans. The shortening of the first ray during distal metatarsal I osteotomy for different osteotomy angles were measured. An algebraic 2-dimensional calculation was done and compared to the results obtained from the 3-dimensional models. RESULTS: Inadvertent shortening of the first metatarsal bone can be as much as 8 mm depending on the amount of intermetatarsal angle (IMA) correction and osteotomy angle. Comparison of the 3 dimensional simulations and the 2 dimensional model resulted in a very strong correlation (R > 0.99 p < 0.00001). Based on our findings an anterior pointing osteotomy of approximately 10° is necessary to restore the length in distal metatarsal I hallux valgus surgery. CONCLUSION: A slight misdirection of the osteotomy plane in distal hallux valgus surgery may result in relevant unwanted alterations in first metatarsal bone length and triangulation by eye is insufficient in this complex geometrical situation without appropriate planning. The present study provides surgeons a practical tool to plan and control the change of first metatarsal length during hallux valgus procedure through exact orientation of the osteotomy angle. If no alteration of length is intended, it may be generalized that an anterior direction of the cut relative to the second metatarsal bone will preserve the length of the first metatarsal bone.

Smoking Is Associated with Anterior Ankle Impingement After Isolated Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus.

OBJECTIVE: To determine potential predictive associations between patient-/lesion-specific factors, clinical outcome and anterior ankle impingement in patients that underwent isolated autologous matrix-induced chondrogenesis (AMIC) for an osteochondral lesion of the talus (OLT). DESIGN: Thirty-five patients with a mean age of 34.7 ± 15 years who underwent isolated cartilage repair with AMIC for OLTs were evaluated at a mean follow-up of 4.5 ± 1.9 years. Patients completed AOFAS (American Orthopaedic Foot and Ankle Society) scores at final follow-up, as well as Tegner scores at final follow-up and retrospectively for preinjury and presurgery time points. Pearson correlation and multivariate regression models were used to distinguish associations between patient-/lesion-specific factors, the need for subsequent surgery due to anterior ankle impingement and patient-reported outcomes. RESULTS: At final follow-up, AOFAS and Tegner scores averaged 92.6 ± 8.3 and 5.1 ± 1.8, respectively. Both body mass index (BMI) and duration of symptoms were independent predictors for postoperative AOFAS and Δ preinjury to postsurgery Tegner with positive smoking status showing a trend toward worse AOFAS scores, but this did not reach statistical significance (P = 0.054). Nine patients (25.7%) required subsequent surgery due to anterior ankle impingement. Smoking was the only factor that showed significant correlation with postoperative anterior ankle impingement with an odds ratio of 10.61 when adjusted for BMI and duration of symptoms (95% CI, 1.04-108.57; P = 0.047). CONCLUSION: In particular, patients with normal BMI and chronic symptoms benefit from AMIC for the treatment of OLTs. Conversely, smoking cessation should be considered before AMIC due to the increased risk of subsequent surgery and possibly worse clinical outcome seen in active smokers.

Talar neck angle correlates with tibial torsion-Guidance for 3D and 2D measurements in total ankle replacement.

Axial plane alignment of the talar component in total ankle arthroplasty is poorly understood and remains a major issue, especially since malpositioning results in increased peak pressure and rotational torque. Further profound knowledge regarding individual anatomy of the talus and its relation to proximal and distal osseous structures is therefore needed. Therefore, three-dimensional (3D) surface models of 50 lower extremities were generated using computed tomography data of patients without ankle osteoarthritis. The talus neck torsion was measured using a novel 3D measurement method. Then, tibial torsion and subtalar joint axis orientation were measured and correlated to the talus neck torsion. Moreover, a 2D measurement method of the talus neck torsion was developed. A statistically significant correlation was found between external tibia torsion and medial talus neck torsion, as well as talus neck axis and subtalar joint axis in the transversal and frontal plane. The novel defined 3D measurement methods indicated excellent inter-rater and intra-rater reliability. The 2D measurement method of the talus neck torsion was in good agreement with the 3D method. The results showed that the rotational profiles of the tibia, talus, and adjacent joints are interconnected, which should be considered in total ankle replacement (TAR). Clinical relevance: This study improves the overall understanding of the talar anatomy, as well as its relationship to adjacent osseous structures. The novel 2D measurement method of the talus neck torsion might improve talar component positioning in the axial plane corresponding to the patient's individual anatomy, and therefore improve the survival rate of TAR.

Treatment of hindfoot and ankle infections with Ilizarov external fixator or spacer, followed by secondary arthrodesis.

An established treatment strategy in surgical site infection after hindfoot and ankle surgery is a two-stage procedure with debridement and placement of a cement spacer, followed by antibiotic treatment and secondary arthrodesis. However, there is little evidence to favor this treatment over a one-stage procedure with debridement, followed by primary arthrodesis with an Ilizarov external fixator and antibiotic treatment. We compared the infection control and clinical and radiological outcome of a two-stage and a one-stage procedure. In this study, 7 patients with a two-stage revision and 11 patients with a one-stage revision between 2005 and 2015 were included. The primary outcome was infection control (absence of the Musculoskeletal Infection Society PJI criteria) 2 years after the ankle or hindfoot arthrodesis. Secondary outcome measures were the AOFAS hindfoot score and radiological consolidation rate. Infection control was 85% (6 out of 7 patients) in the two-stage group and 81% (9 out of 11 patients) in the one-stage group (p = 1.0). One patient (14%) of the two-stage and two patients (18%) in the one-stage group needed below-knee amputation. In the two-stage group, the mean postoperative AOFAS score was 74.8 (SD: ±11.3) versus 71.7 (SD: ±17.8) in the one-stage group. Radiological consolidation could be achieved in 71% in the spacer group (n = 5) and in 72% in the Ilizarov external fixator group (n = 9). Infection control, AOFAS score, and radiologic consolidation of hindfoot and ankle arthrodesis were comparable in both groups of patients with complicated postsurgical hindfoot or ankle infections.

Biomechanics of Ankle Ligament Reconstruction: A Cadaveric Study to Compare Stability of Reconstruction Techniques Using 1 or 2 Fibular Tunnels.

BACKGROUND: Anatomic lateral ankle ligament reconstruction has been proposed for patients with chronic ankle instability. A reliable approach is a reconstruction technique using an allograft and 2 fibular tunnels. A recently introduced approach that entails 1-fibular tunnel reconstruction might reduce the risk of intraoperative complications and ultimately improve patient outcome. HYPOTHESIS: We hypothesized that both reconstruction techniques show similar ankle stability (joint laxity and stiffness) and are similar to the intact joint condition. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 10 Thiel-conserved cadaveric ankles were divided into 2 groups and tested in 3 stages-intact, transected, and reconstructed lateral ankle ligaments-using either the 1- or the 2-fibular tunnel technique. To quantify stability in each stage, anterior drawer and talar tilt tests were performed in 0°, 10°, and 20° of plantarflexion (anterior drawer test) or dorsiflexion (talar tilt test). Bone displacements were measured using motion capture, from which laxity and stiffness were calculated together with applied forces. Finally, reconstructed ligaments were tested to failure in neutral position with a maximal applicable torque in inversion. A mixed linear model was used to describe and compare the outcomes. RESULTS: When ankle stability of intact and reconstructed ligaments was compared, no significant difference was found between reconstruction techniques for any flexion angle. Also, no significant difference was found when the maximal applicable torque of the 1-tunnel technique (9.1 ± 4.4 N·m) was compared with the 2-tunnel technique (8.9 ± 4.8 N·m). CONCLUSION: Lateral ankle ligament reconstruction with an allograft using 1 fibular tunnel demonstrated similar biomechanical stability to the 2-tunnel approach. CLINICAL RELEVANCE: Demonstrating similar stability in a cadaveric study and given the potential to reduce intraoperative complications, the 1-fibular tunnel approach should be considered a viable option for the surgical therapy of chronic ankle instability. Clinical randomized prospective trials are needed to determine the clinical outcome of the 1-tunnel approach.

Long-term Prognosis After Successful Nonoperative Treatment of Osteochondral Lesions of the Talus: An Observational 14-Year Follow-up Study.

BACKGROUND: Little is known about the long-term prognosis of osteochondral lesions of the talus (OLTs) after nonoperative treatment. PURPOSE: To evaluate the clinical and radiological long-term results of initially successfully treated OLTs after a minimum follow-up of 10 years. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1998 and 2006, 48 patients (50 ankles) with OLTs were successfully treated nonoperatively. These patients were enrolled in a retrospective long-term follow-up, for which 24 patients could not be reached or were available only by telephone. A further 2 OLTs (6%) that had been treated surgically were excluded from the analysis and documented as failures of nonoperative treatment. The final study group of 22 patients (mean age at injury, 42 years; range, 10-69 years) with 24 OLTs (mean size, 1.4 cm2; range, 0.2-3.8 cm2) underwent clinical and radiological evaluation after a mean follow-up of 14 years (range, 11-20 years). Ankle pain was evaluated with a visual analog scale (VAS), ankle function with the American Orthopaedic Foot and Ankle Society (AOFAS) score, and sports activity with the Tegner score. Progression of ankle osteoarthritis was analyzed based on plain ankle radiographs at the initial presentation and the final follow-up according to the Van Dijk classification. RESULTS: At final follow-up, the 24 cases (ie, ankles) showed a median VAS score of 0 (IQR, 0.0-2.25) and a median AOFAS score of 94.0 (IQR, 85.0-100). Pain had improved in 18 cases (75%), was unchanged in 3 cases (13%), and had increased in 3 cases (13%). The median Tegner score was 4.0 (IQR, 3.0-5.0). Persistent ankle pain had led to a decrease in sports activity in 38% of cases. At the final follow-up, 11 cases (73%) showed no progression of ankle osteoarthritis and 4 cases (27%) showed progression by 1 grade. CONCLUSION: Osteochondral lesions of the talus that successfully undergo an initial nonoperative treatment period have minimal symptoms in the long term, a low failure rate, and no relevant ankle osteoarthritis progression. However, a decrease in sports activity due to sports-related ankle pain was observed in more than one-third of patients.

The Use of Virtual Planning and Patient-specific Guides to Correct Complex Deformities of the Foot and Ankle.

This article provides an overview regarding the virtual planning and precise execution of corrective osteotomies around the foot and ankle. Based on 3-dimensional data obtained from CT scans, surgeons are able to create a virtual plan of how to correct a complex deformity. This plan is transferred into the production of true patient-specific guides, designed to perform a specific surgical intervention. The authors have extensive experience with this technique and were involved in the development of the method. The current article provides an overview regarding the virtual planning and precise execution of corrective osteotomies around the foot and ankle.

Mid-term walking ability after Charcot foot reconstruction using the Ilizarov ring fixator.

BACKGROUND: Failed conservative treatment and complications are indications for foot reconstruction in Charcot arthropathy. External fixation using the Ilizarov principles offers a one-stage procedure for deformity correction and resection of osteomyelitic bone. The aim of this study was to determine whether external fixation with an Ilizarov ring fixator leads reliably to walking ability. MATERIALS AND METHODS: 29 patients treated with an Ilizarov ring fixator for Charcot arthropathy were retrospectively analyzed. Radiologic fusion at final follow up was assessed separately on conventional X-rays by two authors. The association between walking ability and the presence of osteomyelitis at the time of reconstruction, and the presence of fusion at final follow up was investigated using Fisher's exact test. RESULTS: Mean follow up was 35 months (range 5.3-107) months; mean time of external fixation was 113 days. Ten patients (34.5%) reached fusion, but 19 did not (65.5%). Two patients needed below knee amputation. 26 of the remaining 27 patients maintained walking ability, 23 of those without assistive devices. Walking ability was independent from the presence of osteomyelitis at the time of reconstruction and from the presence of fusion. CONCLUSION: Foot reconstruction with an Ilizarov ring fixator led to limb salvage in 93%. The vast majority (96.3%) of patients with successful limb salvage was ambulatory, independent from radiologic fusion, and presence of osteomyelitis at the time of reconstruction. These findings encourage limb salvage and deformity correction in this difficult-to-treat disease, even with underlying osteomyelitis.