Faculty Bibliography

BACKGROUND:Our purpose was to assess the reliability of measurements of adult-acquired flatfoot deformity (AAFD) taken by investigators of different levels of clinical experience using weightbearing computed tomography (WBCT). METHODS:Nineteen AAFD patients underwent WBCT. Three investigators with different levels of clinical experience made AAFD measurements in axial, coronal, and sagittal planes. Intra- and interobserver reliability were assessed. Mean values for each measurement were compared between investigators. RESULTS:After a training protocol, substantial to perfect intra- and interobserver reliability was observed for most measures, regardless of the investigator's experience level. Significant differences between investigators were observed in 2 of 21 measured parameters: medial cuneiform-first metatarsal angle (P=0.003) and navicular-medial cuneiform angle (P=0.001). CONCLUSIONS:AAFD radiographic measurements can be performed reliably by investigators with different levels of clinical experience using WBCT. LEVEL OF EVIDENCE/METHODS:Level II, prospective comparative study.

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 ± 2.99 vs 1.06 ± 1.43; p < .0001), SF-36 physical component summary (PCS) (28.20 ± 10.71 vs 45.04 ± 11.19; p < .0001) and LEFS (36.13 ± 20.49 vs 58.73 ± 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 ± 3.36 cm vs 7.18 ± 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/METHODS:Observational study, case series - level IV.

BACKGROUND:To investigate the reliability and reproducibility of syndesmosis measurements on weightbearing (WB) cone-beam computed tomography (CBCT) images and compare them with measurements obtained using non-weightbearing (NWB) images. METHODS:In this IRB-approved, retrospective study of 5 men and 9 women with prior ankle injuries, simultaneous WB and NWB CBCT scans were taken. A set of 21 syndesmosis measurements using WB and NWB images were performed by 3 independent observers. Pearson/Spearman correlation and intra-class correlation (ICC) were used to assess intra- and inter-observer reliability, respectively. RESULTS:We observed substantial to perfect intra-observer reliability (ICC=0.72-0.99) in 20 measurements. Moderate to perfect agreement (ICC=0.45-0.97) between observers was noted in 19 measurements. CONCLUSION/CONCLUSIONS:Measurements evaluating the distance between tibia and fibula in the axial plane 10mm above the plafond had high intra- and inter-observer reliability. Mean posterior tibio-fibular distance, diastasis, and angular measurement were significantly different between WB and NWB images.

The biology and function of orthotopic transplantation of Achilles tendon allograft are unknown. Particularly, the revitalization of Achilles allograft is a clinical concern. Achilles allografts were harvested from donor rats and stored at -80 °C. Subcutaneous adipose tissue was harvested from the would-be allograft recipient rats for isolation of mesenchymal stem cells (MSCs). MSCs were cultured with growth differentiation factor-5 (GDF-5) and applied onto Achilles allografts on the day of transplantation. After the native Achilles tendon was resected from the left hind limb of the rats, Achilles allograft, with or without autologous MSCs, was implanted and sutured with calf muscles proximally and calcaneus distally. Animal gait was recorded presurgery and postsurgery weekly. The animals were sacrificed at week 4, and the transplanted Achilles allografts were collected for biomechanical testing and histology. The operated limbs had altered gait. By week 4, the paw print intensity, stance time, and duty cycle (percentage of the stance phase in a step cycle) of the reconstructed limbs were mostly recovered to the baselines recorded before surgery. Maximum load of failure was not different between Achilles allografts, with or without MSCs, and the native tendons. The Achilles allograft supplemented with MSCs had higher cellularity than the Achilles allograft without MSCs. Deposition of fine collagen (type III) fibers was active in Achilles allograft, with or without MSCs, but it was more evenly distributed in the allografts that were incubated with MSCs. In conclusion, orthotopically transplanted Achilles allograft healed with host tissues, regained strength, and largely restored Achilles function in 4 wk in rats. It is therefore a viable option for the reconstruction of a large Achilles tendon defect. Supplementation of MSCs improved repopulation of Achilles allograft, but large animal models, with long-term follow up and cell tracking, may be required to fully appreciate the functional benefits of MSCs.

BACKGROUND:Bunionette deformity is a painful bony prominence of the 5th metatarsal. We evaluated outcomes of using a Kramer osteotomy to treat this condition. METHODS:Retrospective study of patients treated with a Kramer osteotomy from 2003 and 2016. Outcome measures included Foot Functional Index (FFI) and radiographic measurements. RESULTS:angle improved 13.2° from 13.6° preoperatively to 0.4° at final follow-up (p<0.01). There were 5 delayed unions (11.6%) and 1 non-union (2.3%). CONCLUSIONS:angles and few complications.

Introduction/UNASSIGNED:The treatment of osteochondral lesions of the talus (OLTs) recalcitrant to non-surgical interventions is challenging. Particulated juvenile cartilage allograft transplantation (PJCAT) has become a viable treatment option, obviating the need for an osteotomy or second-stage surgery and eliminating risk of donor site morbidity. Short-term outcomes have been promising, but failures associated with PJCAT have not been well described. Case Report/UNASSIGNED:Four patients with OLTs who had continued symptoms after PJCAT underwent a second-look arthroscopic evaluation. The quality of cartilage repair was evaluated using the international cartilage repair society (ICRS) score. Biopsy of the repair was taken for histological analysis. Two patients demonstrated a lack of integration of the allograft into the surrounding cartilage, and two had failures associated with impingement. Three patients' repairs were consistent with a Grade III ICRS score and one with a Grade II score. Histological examination demonstrated fibrotic repair tissue (Type 1 collagen) with depleted proteoglycans and Type II collagen. Conclusion/UNASSIGNED:There were no obvious patients or surgical factors associated with poor outcomes. Integration of PJCAT with surrounding cartilage appears to be affected by biological and mechanical factors. Further, understanding of factors influencing PJCAT integration will help develop more specific indications for use.

OBJECTIVES/OBJECTIVE:To assess high-bandwidth and compressed sensing-(CS)-SEMAC turbo spin echo (TSE) techniques for metal artifact reduction MRI of total ankle arthroplasty (TAA) implants. METHODS:Following institutional approval and consent, 40 subjects with TAA implants underwent 1.5-T MRI prospectively. Evaluations included bone-implant interfaces, anatomical structures, abnormal findings and differential diagnoses before and after MRI. AUCs of P-P plots were used to determine superiority. Statistical differences were evaluated with McNemar and chi-square tests. P-values ≤ 0.05 were considered significant. RESULTS:CS-SEMAC TSE was superior to high-bandwidth TSE in showing the bone-implant interfaces (AUC=0.917), periprosthetic bone, tendons and joint capsule (AUC=0.337-0.766), bone marrow oedema (43 % difference, p=0.041), interface osteolysis (63 %, p=0.015), tendinopathy (62 %, p=0.062), periprosthetic fractures (60 %, p=0.250), synovitis (43 %, p=0.250), as well as reader confidence for bone marrow oedema (p=<0.001), fracture (p=0.001), interface osteolysis (p=0.003), synovitis (p=0.027) and tendinopathy (p=0.034). The number of differential diagnoses in symptomatic subjects after the MRI with CS-SEMAC decreased from 3 (1-4) to 1 (1-2) (p<0.001). CONCLUSIONS:MRI of TAA implants with CS-SEMAC improves the diagnosis of interface osteolysis, periprosthetic bone marrow oedema, fractures and tendinopathy when compared to high-BW TSE, and has a positive effect on patient management. KEY POINTS/CONCLUSIONS:• High-bandwidth TSE and compressed sensing SEMAC improve MRI of ankle arthroplasty implants. • Compressed sensing SEMAC improves bone-implant interfaces, periprosthetic bone, tendons and joint capsule visibility. • Compressed sensing SEMAC improves the diagnosis of osteolysis, tendinopathy, fractures and synovitis. • MRI decreases the number of clinical differential diagnoses of painful ankle arthroplasty implants.

Our goal was to develop a novel technique for inducing Achilles tendinopathy in animal models which more accurately represents the progressive histological and biomechanical characteristic of chronic Achilles tendinopathy in humans. In this animal research study, forty-five rabbits were randomly assigned to three groups and given bilateral Achilles injections. Low dose (LD group) (n = 18) underwent a novel technique with three low-dose (0.1mg) injections of collagenase that were separated by two weeks, the high dose group (HD) (n = 18) underwent traditional single high-dose (0.3mg) injections, and the third group were controls (n = 9). Six rabbits were sacrificed from each experimental group (LD and HD) at 10, 12 and 16 weeks. Control animals were sacrificed after 16 weeks. Histological and biomechanical properties were then compared in all three groups. At 10 weeks, Bonar score and tendon cross sectional area was highest in HD group, with impaired biomechanical properties compared to LD group. At 12 weeks, Bonar score was higher in LD group, with similar biomechanical findings when compared to HD group. After 16 weeks, Bonar score was significantly increased for both LD group (11,8±2,28) and HD group (5,6±2,51), when compared to controls (2±0,76). LD group showed more pronounced histological and biomechanical findings, including cross sectional area of the tendon, Young's modulus, yield stress and ultimate tensile strength. In conclusion, Achilles tendinopathy in animal models that were induced by serial injections of low-dose collagenase showed more pronounced histological and biomechanical findings after 16 weeks than traditional techniques, mimicking better the progressive and chronic characteristic of the tendinopathy in humans.