Correction of progressive collapsing foot deformity classes after isolated arthroscopic subtalar arthrodesis.

INTRODUCTION: Subtalar osteoarthritis in the context of flatfoot (recently renamed Progressive Collapsing Foot Deformity (PCFD)) may be treated through subtalar joint (SJ) arthrodesis with anticipated consequences on three-dimensional bony configuration. This study investigates the correction of PCFD-related deformities achieved after Anterolateral Arthroscopic Subtalar Arthrodesis (ALAPSTA). METHODS: In this retrospective study, we evaluated pre- and post-operative (at 6 months) weight bearing computed tomography (WBCT) images of patients diagnosed with PCFD with a degenerated SJ (2 A according to PCFD classification) and/or peritalar subluxation (2D) with or without associated flexible midfoot and/or forefoot deformities (1B, 1 C and 1E) which underwent ALAPSTA as a standalone procedure between 2017 and 2020. Multiple measurements were used to assess and compare pre and post-operative PCFD classes. RESULTS: Thirtythree PCFD (33 patients, median age 62) were included in the study. Preoperative medial facet subluxation was 28.3 % (IQR, 15.1 to 49.3 %). Overall PCFD 3D deformity improved with a reduction of the foot and ankle offset from 9.3 points (IQR, 7.8 to 12) to 4 (IQR, 0.9 to 7) (p < 0.001). Class A-hindfoot valgus (median tibiocalcaneal angle and median calcaneal moment arm improved by 9.4 degrees (p < 0.001) and 11 mm (p < 0.001), respectively), class B-midfoot abduction (median talonavicular coverage angle improved by 20.5 degrees, p < 0.001) and class C-forefoot varus (median sagittal talo-first metatarsal angle improved by 10.2 degrees (p < 0.001)) were significantly corrected after surgery. Class D was difficult to assess due to the fusion procedure. No patient had a pre-operative valgus deformity at the ankle (no class E), and no significant change of the talar tilt was observed (p = 0.12). CONCLUSION: In this series, ALAPSTA performed as a standalone procedure to treat patients diagnosed with PCFD with a degenerated subtalar joint and/or peritalar subluxation was effective not only at correcting hindfoot alignment but also flexible midfoot abduction and flexible forefoot varus. LEVEL OF EVIDENCE: Level IV, case series.

Hindfoot alignment assessment by the foot-ankle offset: a diagnostic study.

INTRODUCTION: Foot-ankle offset (FAO) is a three-dimensional (3D) biometric measurement of hindfoot alignment (HA) measured on images from weight-bearing computed tomography (WBCT). Our aim was to investigate its distribution in a large cohort of patients, hypothesizing that threshold FAO values in valgus or varus could be identified as markers for increased risk of associated pathologies. MATERIALS AND METHODS: Prospective, monocentric, level II study including 125 subjects (250 feet) undergoing bilateral WBCT [58.4% female; mean age, 54 years (18-84)]. Patients were clinically assessed and pathologies were classified according to anatomic location (valgus- or varus associated). HA was measured using FAO on 3D datasets and tibio-calcaneal angles (TCA) on two-dimensional Saltzman-El-Khoury views. Threshold FAO values and area under the receiver operating characteristics curve (AUC) were calculated for predicting increased risk of medial or lateral pathologies. RESULTS: Mean FAO was 1.65% ± 4.72 and mean TCA was 4.15° ± 7.67. Clinically, 167 feet were normal, 33 varus and 50 valgus with FAO values of 1.71% ± 3.16, - 4.96% ± 5.30 and 5.79% ± 3.77, respectively. Mean FAO was 0.99% ± 3.26 for non-pathological feet, - 2.53% ± 5.05 for lateral and 6.81% ± 2.70 for medial pathologies. Threshold FAO values of - 1.64% (51.4% sensitivity, 85.1% specificity, AUC = 0.72) and 2.71% (95% sensitivity, 82.8% specificity, AUC = 0.93) best predicted the risk of lateral and medial pathology, respectively. CONCLUSION: Patients with FAO between - 1.64% and 2.71% had the least risk of degenerative foot and ankle pathology. This interval could be considered a target for patients undergoing realignment procedures. CLINICAL RELEVANCE: A "safe zone" for Foot Ankle Offset was described between - 1.64% and 2.71%, for which the risk of foot and ankle pathologies is lower. LEVEL OF EVIDENCE: II-Diagnostic study.

Prevalence and pattern of lateral impingements in the progressive collapsing foot deformity.

INTRODUCTION: The prevalence of lateral bony impingements [i.e., Sinus Tarsi (STI), Talo-Fibular (TFI) and Calcaneo-Fibular (CFI)] and their association with Peritalar Subluxation (PTS) have not been clearly established for progressive collapsing foot deformity (PCFD).This study aims to assess the prevalence of STI, TFI and CFI in PCFD, in addition to their association with PTS. We hypothesized that STI and TFI would be more prevalent than CFI. MATERIALS AND METHODS: Seventy-two continuous symptomatic PCFD cases were retrospectively reviewed. Weightbearing computed tomography (WBCT) was used to assess lateral impingements and classified as STI, TFI and CFI. PTS was assessed by the percent of uncovered and the incongruence angle of the middle facet, and the overall foot deformity was determined by the foot and ankle offset (FAO). Data were collected by two fellowship-trained independent observers. RESULTS: Intra-observer and inter-observer reliabilities for impingement assessment ranged from substantial to almost perfect. STI was present in 84.7%, TFI in 65.2% and CFI in 19.4%. PCFD with STI showed increased middle facet uncoverage (p = 0.0001) and FAO (p = 0.0008) compared to PCFD without STI. There were no differences in FAO and middle facet uncoverage in PCFD with TFI and without TFI. PCFD with CFI was associated with STI in 100% of cases. PCFD with CFI showed decreased middle facet incongruence (p = 0.04) and higher FAO (p = 0.006) compared to PCFD without CFI. CONCLUSIONS: STI and TFI were more prevalent than CFI in PCFD. However, only STI was associated with PTS. Conversely, CFI was associated with less PTS, suggesting a different pathological mechanism which could be a compensatory subtalar behavior caused by deep layer failure of the deltoid ligament and talar tilt.

Weightbearing CT assessment of foot and ankle joints in Pes Planovalgus using distance mapping.

INTRODUCTION: The goal of this study was to describe the abnormal joint surface interaction at the ankle, hindfoot and midfoot joints in patients presenting with Pes Planovalgus (PPV) using three-dimensional (3D) distance mapping on weightbearing computed tomography (WBCT) images by comparing a series of PPVs to a series of normally-aligned feet. We hypothesized that in PPVs joint interactions would reveal significantly increased spaces in the medial side of the ankle, hindfoot and midfoot joints. METHODS: In this case-control study, ten feet (10 patients) with asymptomatic PPV were compared to 10 matched-paired (by age, gender and body mass index) normally-aligned feet (10 patients). Three-dimensional models were produced from the images and distance maps representing joint surface configuration were generated for the ankle, hindfoot and midfoot joints. The distance maps for each joint were then compared between the two groups and between regions in the same group. RESULTS: In PPV patients there was a significantly increased surface-to-surface distance anteromedially at the ankle joint (+46.3%, p < 0.001) along with an increased distance on the anterior halves of both the medial (+21.3%, p = 0.098) and lateral malleoli (+22.7%, p = 0.038). At the posterolateral corner of the posterior facet of the subtalar joint we found an increased surface-to-surface distance (by 57.1%, p < 0.001), while at the talonavicular joint there was a reduction of the distance at the superomedial corner (-20%, p = 0.097) along with a significant increase in the upper central (+20%, p = 0.039) and lateral (+30.7%, p = 0.015) zones. A reduction of the surface-to-surface distance was also observed in three of the four zones of the calcaneocuboid joint. Finally, a statistically significant increase in the mean distance was observed at the naviculocuneiform and tarsometatarsal joints in a range between 38% and 93.4% (p < 0.001 in all cases). CONCLUSION: We found significant differences in surface-to-surface interaction at the foot and ankle joints between Pes Planovalgus and normally-aligned controls. Distance mapping on WBCT images could be used in clinical practice as a diagnostic support to gauge the morphological changes of articular spaces occurring in Pes Planovalgus. LEVEL OF EVIDENCE: Level III, case-control study.

Diagnostic accuracy of measurements in progressive collapsing foot deformity using weight bearing computed tomography: A matched case-control study.

BACKGROUND: We aimed to investigate the diagnostic accuracy of known two-dimensional (2D) and three-dimensional (3D) measurements for Progressive Collapsing Foot Deformity (PCFD) in weight-bearing computed tomography (WBCT). We hypothesized that 3D biometrics would have better specificity and sensitivity for PCFD diagnosis than 2D measurements. METHODS: This was a retrospective case-control study, including 28 PCFD feet and 28 controls matched for age, sex and Body Mass Index. Two-dimensional measurements included: axial and sagittal talus-first metatarsal angles (TM1A and TM1S), talonavicular coverage angle (TNCA), forefoot arch angle (FFAA), middle facet incongruence angle (MF°) and uncoverage percentage (MF%). The 3D Foot Ankle Offset (FAO) was obtained using dedicated semi-automatic software. Intra and interobserver reliabilities were assessed. Receiver Operating Characteristic (ROC) curves were calculated to determine diagnostic accuracy (Area Under the Curve (AUC)), sensitivity and specificity. RESULTS: In PCFD, mean MF% and MF° were respectively 47.2% ± 15.4 and 13.3° ± 5.3 compared with 13.5% ± 8.7 and 5.6° ± 2.9 in controls (p < 0.001). The FAO was 8.1% ± 3.8 in PCFD and 1.4% ± 1.7 in controls (p < 0.001). AUCs were 0.99 (95%CI, 0.98-1) for MF%, 0.96 (95%CI, 0.9-1) for FAO, 0.90 (95%CI, 0.81-0.98) for MF°. For MF%, a threshold value equal or greater than 28.7% had a sensitivity of 100% and specificity of 92.8%. Conversely, a FAO value equal or greater than 4.6% had a specificity of 100% and a sensitivity of 89.2%. All other 2D measurements were significantly different in PCFD and controls (p < 0.001). CONCLUSIONS: MF% and FAO were both accurate measurements for PCFD. MF% demonstrated slightly better specificity. FAO better sensitivity. A combination of threshold values of 28.7% for MF% and 4.6% for FAO yielded 100% sensitivity and specificity.

The use of three-dimensional biometric Foot and Ankle Offset to predict additional realignment procedures in total ankle replacement.

BACKGROUND: Decision to perform associated corrective alignment procedures in patients undergoing total ankle replacement (TAR) is commonly made intraoperatively. The Foot and Ankle Offset (FAO) can evaluate multiplanar deformity and be an effective instrument in surgical planning. This study objective was to assess the ability of this tool to predict the need for additional realignment procedures at the time of TAR. METHODS: In this retrospective study, we enrolled 21 patients who underwent TAR and had preoperative WBCT studies. Two independent and blinded observers calculated the preoperative FAO using dedicated software. FAO measurements were compared between the different alignment groups (physiological alignment, valgus and varus). A multivariate regression analysis was used to assess the correlation between performed realignment procedures and FAO values. RESULTS: Mean preoperative FAO was 4.4% (95%CI = 1.4-7.5). The number of osseous realignment procedures needed was found to correlate positively and significantly with FAO (p = .001). The number of osseus procedures needed was significantly higher in patients with valgus malalignment (p = .009). Patients with valgus malalignment needing a medial column procedure had a relative risk of 6.3 when compared to varus malalignment patients (p = .02). CONCLUSION: The number of additional bony realignment procedures performed at the time of TAR significantly correlated with preoperative FAO and that the number of osseus procedures needed was significantly higher in patients with valgus malalignment. Such biometric tools may enhance the preoperative assessment and surgical planning for patients undergoing TAR, with the potential to optimize surgical outcomes.

Tibiotalar Incongruency in Clubfoot Treated Operatively Is a Predictor of Worse Outcome at a Mean of 26 Years.

The traditional approach to congenital talipes equinovarus (CTEV) has relied on stepwise manipulations, followed by surgery in severe or recurrent cases. The 3 aims of this study were: (1) to report long-term results of clubfoot treated by posterior capsulectomy and selective release (PCSR); (2) to determine the reliability of a visual scale in the assessment of intraoperative tibiotalar incongruency (TTI); and, (3) to assess the role of TTI as a prognostic factor. We reviewed data regarding 95 CTEV (65 patients) treated by PCSR at a minimum follow-up of 20 years. Patients underwent a physical and radiographic examination, and were assessed through multiple clinical scores. The inter- and intraobserver reliability for TTI evaluation was calculated on clinical photographs. Based on TTI, 52 CTEV were divided in 2 groups (30 congruent vs 22 incongruent) and compared. At a mean follow-up of 26.8 (from 24 to 31) years, 52 CTEV (38 patients) were available for the analysis. Functional results were globally satisfactory. The inter- (κ = 0.748) and intraobserver analysis (κ = 0.688) for the TTI visual assessment showed substantial agreement. In patients with incongruency, patient reported outcomes were significantly worse, with also a greater development of subtalar (p = .02), talonavicular and calcaneocuboid arthritis (p < .001 for both). In treating severe CTEV, the surgical PCSR performed in the first year of life obtains satisfactory clinical and patient-recorded outcomes at over 25 years of follow-up. The visual assessment of TTI is reproducible and potentially represents a long-term prognostic factor.

Distance mapping of the foot and ankle joints using weightbearing CT: The cavovarus configuration.

INTRODUCTION: The goal of this study was to characterize the abnormal joint surface interaction at the ankle, hindfoot and midfoot joints of the cavovarus foot using distance mapping on weightbearing computed tomography (WBCT) images by comparing a series of cavovarus feet to a series of normally-aligned feet. METHODS: In this case-control study, ten feet (10 patients) with asymptomatic cavovarus shape (cases; N = 10) were compared to 10 matched-paired (by age, gender and body mass index) normally-aligned feet (10 patients) (controls; N = 10). Three-dimensional models were produced from the images and distance maps representing joint surface configuration were generated for the ankle, hindfoot and midfoot joints. The distance maps for each joint were then compared between the two groups and between regions in the same group. RESULTS: In the cavovarus group there was a significant increase in surface-to-surface distance at the posterior tibiotalar joint and a reduced distance at the anterior part, together with a greater distance at the posterior half of the medial gutter. Also, a decrease in surface-to-surface distance on the anterior half of the anterior facet and an increased distance on the posterior quadrants of the posterior facet of the subtalar joint were found. At the sinus tarsi, the lateral aspect of the talonavicular joint, the naviculocuneiform and the tarsometatarsal joints there was a statistically significant increase in surface-to-surface distance in cavovarus patients as compared to controls. CONCLUSION: Distance mapping analysis on WBCT images identified significant differences in surface-to-surface interaction at the foot and ankle joints between cavovarus and normally-aligned feet. LEVEL OF EVIDENCE: Level III, case-control study.

Podoscopic classification of second toe deformities.

BACKGROUND: The AFCP (French Association of Foot Surgery) classification was recently introduced as a reliable and quick visual method for the assessment of sagittal plane deformities of the second toe. The aim of this study was four-fold: (1) to describe a new toe-ground area score (TAS) as an additional dynamic tool of such classification, (2) to verify whether all second toe deformities could be classified, (3) to assess the TAS intra- and inter-observer reliability and (4) to evaluate the TAS learning curve. METHODS: In this retrospective study 52 s toes were evaluated using a podoscope. Ten foot and ankle surgeons assessed independently standardised videos of each case acquired in a blinded fashion. Assessment was repeated three times, 15 days apart. Intra- (Intraclass Correlation Coefficient or ICC) and inter-observer reliability (Fleiss' Kappa coefficient) were calculated. Mean time to assess a deformity was also recorded. RESULTS: All the 522 observations (52 feet assessed by 10 surgeons) were successfully rated using the TAS. Intra- and inter-observer reliability were substantial for the first round (ICC: 0.79; Kappa: 0.76) and excellent for the second (ICC: 0.88; Kappa: 0.8) and third round (ICC: 0.84; Kappa: 0.81). Mean assessment time ± standard deviation was 22 ± 11 s per case for the last two rounds. CONCLUSIONS: The TAS has been proven reliable and quick in the assessment of second toe deformities. When combined with a static segmentary classification of the toe (such as the AFCP classification) it might provide further dynamic informations about the ability of the toe to engage the ground. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

A comparative study between isolated gastrocnemius tightness patients and controls by quantitative Gait analysis and baropodometry.

BACKGROUND: Isolated gastrocnemius tightness (IGT) has been suggested as an etiologic factor in mechanical disorders of the foot and ankle without a clear pathophysiological mechanism in the literature. We hypothesized that restricted ankle dorsiflexion inducing increased forefoot pressure in IGT patients could be this pathophysiological mechanism. METHODS: Case/control experimental observational investigation. Forty lower limbs in 20 asymptomatic IGT patients were included and compared to controls. Quantitative gait analyses coupled with dynamic baropodometry were used for comparison between groups. The primary outcome was maximum ankle dorsiflexion during stance phase. Secondary outcomes were knee flexion and forefoot pressure. RESULTS: Maximum ankle dorsiflexion and maximum forefoot pressure were similar between groups. Increased knee flexion was found in the asymptomatic IGT group. CONCLUSIONS: IGT induced compensatory knee flexion during stance phase, which probably prevents increased pressure on the forefoot by allowing ankle dorsiflexion. LEVEL OF EVIDENCE: Level IV, Case/control experimental observational investigation.

Combined weightbearing CT and MRI assessment of flexible progressive collapsing foot deformity.

BACKGROUND: The objective of this study was to evaluate the correlation between Weightbearing CT (WBCT) markers of pronounced peritalar subluxation (PTS) and MRI findings of soft tissue insufficiency in patients with flexible Progressive Collapsing Foot Deformity (PCFD). We hypothesized that significant correlation would be found. METHODS: Retrospective comparative study with 54 flexible PCFD patients. WBCT and MRI variables deformity severity were evaluated, including markers of pronounced PTS, as well as soft tissue degeneration. A multiple regression analysis and partition prediction models were used to evaluate the relationship between bone alignment and soft tissue injury. P-values of less than .05 were considered significant. RESULTS: Degeneration of the posterior tibial tendon was significantly associated with sinus tarsi impingement (p = .04). Spring ligament degeneration correlated to subtalar joint subluxation (p = .04). Talocalcaneal interosseous ligament involvement was the only one to significantly correlate to the presence of subfibular impingement (p = .02). CONCLUSION: Our results demonstrated that WBCT markers of pronounced deformity and PTS were significantly correlated to MRI involvement of the PTT and other important restraints such as the spring and talocalcaneal interosseus ligaments. LEVEL OF EVIDENCE: Level III, Retrospective comparative study.

Results of more than 11,000 scans with weightbearing CT - Impact on costs, radiation exposure, and procedure time.

BACKGROUND: Weightbearing CT (WBCT) has been proven to more precisely measure bone position than conventional weightbearing radiographic series (R) and conventional CT (CT). The purpose of this study was to assess the benefit of using WBCT instead of R and/or CT as the standard imaging modality, evaluating image acquisition time, radiation dose, and cost-effectiveness. METHODS: All patients who obtained a WBCT as part of standard of care from July 1, 2013 until March 15, 2019 were included in the study. Image acquisition time (T), radiation dose (RD) per patient, and cost-effectiveness were analyzed and compared between the time period using WBCT (yearly average) and the parameters from 2012, i.e. before the availability of WBCT (RCT group). RESULTS: 11,009 WBCT scans were obtained from 4987 patients (4,987 scans (45%) before treatment; 6,022 scans (55%) at follow-up). On a yearly average, 1,957 WBCTs (bilateral scans) and an additional 10.6 CTs (bilateral feet and ankles) were obtained (WBCT group). In 2012, 1,850 Rs (bilateral feet, dorsoplantar and lateral, metatarsal head skyline view) and 254 CTs were obtained from 885 patients (RCT group). The mean yearly RD was 4.3/4.8uSv for the WBCT/RCT groups (mean difference of .5uSv; a decrease of 10% for the WBCT group; p<.01). Yearly mean T was 114/493h in total (3.3/16.0min per patient) for WBCT/RCT groups (mean difference of 379h; a 77% decrease for the WBCT group; p<.01). Yearly cost-effectiveness was a mean profit of 43,959/-723 Euros for WBCT/RCT groups. CONCLUSIONS: 11,009 WBCT scans from 4,987 patients over a period of 5.6 years at a foot and ankle department resulted in 10% decreased RD, 77% decreased T, and increased financial profit (51 Euros per patient) for the institution.

Intra- and inter-observer reliability of the AFCP classification for sagittal plane deformities of the second toe.

BACKGROUND: The French Association of Foot Surgery (AFCP) recently proposed a morphological classification of lesser toe deformities, describing the position of each joint (metatarsophalangeal or MTP, proximal interphalangeal or PIP and distal interphalangeal or DIP) in relation to their anatomic position in the sagittal plane. A study was designed to test its reliability for assessment of sagittal plane deformities of the second toe. METHODS: In this retrospective study 55 toes (55 feet, 50 patients) were evaluated. Eleven foot and ankle surgeons assessed independently standardized photographs of each case acquired in a blinded fashion. Assessment was repeated three times, each 15 days apart. Intra- (Intraclass Correlation Coefficient or ICC) and inter-observer reliability (Fleiss' Kappa coefficient) were calculated for each joint. RESULTS: Intra- and inter-observer reliability were moderate for the MTP joint (ICC range, 0.54-0.61) (Kappa range, 0.53-0.61) and substantial for the PIP (ICC range, 0.60-0.71) (Kappa range, 0.68-0.75) and DIP joints (ICC range, 0.69-0.78) (Kappa range, 0.74-0.78). Mean assessment time±standard deviation was 35±10s per case. CONCLUSIONS: The AFCP classification proved itself reliable in the assessment of sagittal plane defomities of the second toe among eleven foot and ankle surgeons. It is based only on a visual description of the deformity, and does not provide informations on either the clinical reducibility of the deformity and the radiographic joint status. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Hindfoot alignment of adult acquired flatfoot deformity: A comparison of clinical assessment and weightbearing cone beam CT examinations.

BACKGROUND: Clinical assessment of hindfoot alignment (HA) in adult acquired flatfoot deformity (AAFD) can be challenging and weightbearing (WB) cone beam CT (CBCT) may potentially better demonstrate this three-dimensional (3D) deformity. Therefore, we compared clinical and WB CBCT assessment of HA in patients with AAFD. METHODS: In this prospective study, we included 12 men and 8 women (mean age: 52.2, range: 20-88) with flexible AAFD. All subjects also underwent WB CBCT and clinical assessment of hindfoot alignment. Three fellowship-trained foot and ankle surgeons performed six hindfoot alignment measurements on the CT images. Intra- and Inter-observer reliabilities were calculated using intra-class correlation (ICC). Measurements were compared by paired T-tests, and p-values of less than 0.05 were considered significant. RESULTS: The mean of clinically measured hindfoot valgus was 15.2 (95% confidence interval [CI]: 11.5-18.8) degrees. It was significantly different from the mean values of all WB CBCT measurements: Clinical Hindfoot Alignment Angle, 9.9 (CI: 8.9-11.1) degrees; Achilles tendon/Calcaneal Tuberosity Angle, 3.2 (CI: 1.3-5.0) degrees; Tibial axis/Calcaneal Tuberosity Angle, 6.1 (CI: 4.3-7.8) degrees; Tibial axis/Subtalar Joint Angle 7.0 (CI: 5.3-8.8) degrees, and Hindfoot Alignment Angle 22.8 (CI: 20.4-25.3) degrees. We found overall substantial to almost perfect intra- (ICC range: 0.87-0.97) and inter-observer agreements (ICC range: 0.51-0.88) for all WB CBCT measurements. CONCLUSIONS: Using 3D WB CBCT can help characterize the valgus hindfoot alignment in patients with AAFD. We found the different CT measurements to be reliable and repeatable, and to significantly differ from the clinical evaluation of hindfoot valgus alignment. LEVEL OF EVIDENCE: Level II-prospective comparative study.

Tendoscopy of Achilles, peroneal and tibialis posterior tendons: An evidence-based update.

BACKGROUND: Tendoscopy has been proposed in treating several conditions affecting tendons around the ankle. We reviewed literature to investigate the efficacy of Achilles, peroneal and tibialis posterior tendoscopy. METHODS: Following the PRISMA checklist, the Medline, Scopus and EMBASE databases were searched, including studies reporting patients affected by disorders of Achilles, peroneal and tibialis posterior tendons and treated by tendoscopy (or tendoscopic-assisted procedures). The tendoscopic technique, rehabilitation protocol, clinical scores, patient satisfaction, success and failure rates and complications were evaluated. RESULTS: Sixteen studies (319 procedures) dealt with Achilles tendoscopy, nine (108) and six (78) about peroneal and tibialis posterior, respectively. Wound healing, cosmetic results, complication rate, work and sport resumption delay were satisfactory. Clinical scores, classification methods and rehabilitation protocols adopted were heterogeneous. CONCLUSIONS: The recent scientific evidence suggests that tendoscopy and endoscopic-assisted percutaneous procedures are a safe and effective treatment in chronic and acute disorders of tendons around the ankle.

Influence of lower limb rotation on hindfoot alignment using a conventional two-dimensional radiographic technique.

BACKGROUND: Rotation is one of the variables explaining lack of reproducibility in assessing hindfoot alignment. The hypothesis for this study was that a mathematical model predicts how this modifies radiographic hindfoot alignment measurements. METHODS: A cadaveric lower limb, disjointed at knee level, was used. Sagittal and coronal planes were fixed using a custom clamp. Standard AP views were shot every five degrees and measured hindfoot alignments were compared to theoretical values obtained from a mathematical simulation. RESULTS: Hindfoot angle was 7.04° at 0° rotation and 2.11° at -90°. Intra-class and inter-investigator correlation was 0.863. The t-test showed no significant difference (p=0.73). Intra-investigator correlation was 0.957. The R2 correlation index was 0.852. CONCLUSIONS: The mathematical model accurately predicted the variations of the hindfoot angle which was maximum when the foot was aligned with the X-rays source. It then decreased when the foot rotated away, following a parabolic curve.

Acetabular reconstruction using a free fibular autograft in total hip arthroplasty revisions.

PURPOSE: Acetabular reconstruction for segmentary bone loss aims for primary stability and long-lasting integration. The use of a fibular autograft has been described after tumour resection and in traumatology. The hypothesis of this study is that it offers a mechanically reliable solution with good functional results and acceptable morbidity. METHODS: This is a two center retrospective study of 26 operated hips. Indication was mechanical loosening in every case. The operative technique included fibular grafting of a segmental bone loss associated with an acetabular metal reinforcement. RESULTS: Mean follow up was 88 months (three to 165). The PMA score increased from 8.5 (five to 12) to 15 (six to 18) (p <0.001). Acetabular migration was 2 mm (0-4) vertically and 1 mm (0-2) medially. Three graft failures were observed. No major morbidity was observed. CONCLUSION: Fibular autograft after mechanical loosening and segmentary bone loss in total hip arthroplasty revisions offers a mechanically reliable solution for acetabular reconstruction. The results seem to be at least equivalent to other techniques.