Outcomes of flexor digitorum longus (FDL) tendon transfer in the treatment of Achilles tendon disorders.

BACKGROUND: In patients with chronic Achilles tendon disorders, Achilles tendon debridement can be supplemented with a tendon transfer, with the flexor hallucis longus tendon (FHL) transfer representing the most common used technique. Our study describes clinical and functional results of patients treated with flexor digitorum longus (FDL) tendon transfer in the treatment of patients with chronic Achilles tendon disorders. METHODS: Retrospective study of prospectively collected data of thirteen patients (15 feet) that underwent FDL tendon transfer as part of the treatment of chronic Achilles tendon disorders. Preoperative and postoperative assessment included visual analogue score (VAS) for pain, SF-36 survey and lower extremity functional scale (LEFS). The average follow-up was 26.4 (range, 14-56) months. Patients were also assessed for ability to perform single leg heel rise test, muscle power for plantar flexion of the lesser toes, surgical scar condition and associated complications. RESULTS: At final follow-up, we found significant postoperative improvement in VAS score (6.6 ±â€¯2.99 vs 1.06 ±â€¯1.43; p < .0001), SF-36 physical component summary (PCS) (28.20 ±â€¯10.71 vs 45.04 ±â€¯11.19; p < .0001) and LEFS (36.13 ±â€¯20.49 vs 58.73 ±â€¯18.19; p < .0001). Twelve patients (92%) could perform a single leg heel rise test in the operated extremity, although there was significant difference when comparing operated and uninvolved sides (4.86 ±â€¯3.36 cm vs 7.18 ±â€¯3.40 cm; p = .0002). One patient reported weakness for plantar flexion of the lesser toes, without balance or gait disturbances. Two patients (2 feet, 13.3%) had superficial infections and one patient (one foot, 6.6%) needed operative debridement for a deep infection. CONCLUSIONS: FDL tendon transfer represent an operative alternative in the treatment of chronic Achilles tendon disorders. Our study showed good clinical outcomes with low complications and donor site morbidity. LEVEL OF EVIDENCE: Observational study, case series - level IV.

Metal artifact reduction MRI for total ankle replacement sagittal balance evaluation.

BACKGROUND: Restoration of anatomical relationship between talus and tibia is crucial for longevity of total ankle replacement (TAR). Weight-bearing (WB) radiographs are the standard for evaluating the sagittal balance alignment, but are prone to rotational misalignment and altered measurements. Metal artifact reduction sequence (MARS) MRI allows visualization of periprosthetic landmarks and alignment of the image plane to the true sagittal axis of the implant. The purpose of this study was to compare TAR sagittal balance measurements on MARS MRI and WB radiographs. METHODS: Twenty-three subjects with TAR [10 men/13 women, age 60 (41-73) years; 13 (3-24) months post-op] underwent MARS MRI and standard lateral WB radiographs. Standardized MARS MR images were aligned to the sagittal talar component axis. Three observers performed sagittal balance alignment measurements twice in an independent, random and blinded fashion. Lateral Talar Station (LTS), tibial axis-to-talus (T-T) ratio and normalized tibial axis-to-lateral-process (T-L) distance were measured. Concordance correlation coefficients (CCC) and intraclass correlation coefficients (ICC) were used for statistical analysis. In addition, mixed effects linear models were employed to assess overall concordance of the two image types. RESULTS: The intraobserver agreement was excellent for radiographic (CCC=0.96) and MRI (CCC=0.90-0.97) measurements. Interobserver agreements were good-to-excellent with overall slightly higher agreements for MRI (ICC=0.78-0.94) than radiography (ICC=0.78-0.90) measurements. The T-T ratios of radiographs and MRI showed a high degree of concordance, whereas LTS was significantly lower on MRI when compared with radiographs, and T-L distance showed notable disagreement between the two imaging types. CONCLUSION: Sagittal balance measurements performed on standardized weight-bearing radiographs and standardized MARS MRI demonstrate substantial correlation and similarity. Given its high intra and interobserver agreement, MARS MRI may be helpful for the evaluation of TAR sagittal balance. LEVEL OF EVIDENCE: Level II - Prospective Comparative 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.

Flexible Adult Acquired Flatfoot Deformity: Comparison Between Weight-Bearing and Non-Weight-Bearing Measurements Using Cone-Beam Computed Tomography.

BACKGROUND: The 3-dimensional nature of adult acquired flatfoot deformity can be challenging to characterize using radiographs. We tested the hypothesis that measurements on weight-bearing (WB) cone-beam computed tomography (CT) images were more useful for demonstrating the severity of the deformity than non-weight-bearing (NWB) measurements. METHODS: We prospectively enrolled 12 men and 8 women (mean age, 52 years; range, 20 to 88 years) with flexible adult acquired flatfoot deformity. The subjects underwent cone-beam CT while standing (WB) and seated (NWB), and images were assessed in the sagittal, coronal, and axial planes by 3 independent observers who performed multiple measurements. Intraobserver and interobserver reliabilities were assessed with the Pearson or Spearman correlation and the intraclass correlation coefficient (ICC), respectively. Measurements were compared using paired Student t tests or Wilcoxon rank-sum tests. P < 0.05 was considered significant. RESULTS: We found that overall the measurements had substantial intraobserver and interobserver reliability on both the NWB images (mean ICC, 0.80; range, 0.49 to 0.99) and the WB images (mean ICC, 0.81; range, 0.39 to 0.99). Eighteen of 19 measurements differed between WB and NWB cone-beam CT images, with more pronounced deformities on the WB images. The most reliable measurements, based on intraobserver and interobserver reliabilities and the difference between WB and NWB images, were the medial cuneiform-to-floor distance, which averaged 29 mm (95% confidence interval [CI] = 28 to 31 mm) on the NWB images and 18 mm (95% CI = 17 to 19 mm) on the WB images, and the forefoot arch angle (mean, 13° [95% CI = 12° to 15°] and 3.0° [95% CI = 1.4° to 4.6°], respectively) in the coronal view and the cuboid-to-floor distance (mean, 22 mm [95% CI = 21 to 23 mm] and 17 mm [95% CI = 16 to 18 mm], respectively) and the navicular-to-floor distance (mean, 38 mm [95% CI = 36 to 40 mm] and 23 mm [95% CI = 22 to 25 mm], respectively) in the sagittal view. CONCLUSIONS: Measurements analogous to traditional radiographic parameters of adult acquired flatfoot deformity are obtainable using high-resolution cone-beam CT. Compared with NWB images, WB images better demonstrated the severity of osseous derangement in patients with flexible adult acquired flatfoot deformity. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Anatomic Spring Ligament and Posterior Tibial Tendon Reconstruction: New Concept of Double Bundle PTT and a Novel Technique for Spring Ligament.

A new technique in spring ligament reconstruction using medial half of posterior tibial tendon is demonstrated as a means of supporting the arch. In addition a new concept of double bundle PTT reconstruction based on anatomical attachments of original PTT is presented with the goal of obtaining the full function of PTT.