Cavovarus With a Twist: Midfoot Coronal and Axial Plane Rotational Deformity in Charcot-Marie-Tooth Disease

Background: The cavovarus deformity of Charcot-Marie-Tooth (CMT) disease is often characterized by a paradoxical relationship of hindfoot varus and forefoot valgus. The configuration of the midfoot, which links these deformities, is poorly understood. Accurate assessment of 3-dimensional alignment under physiologic loadbearing conditions is possible using weightbearing computed tomography (WBCT). This is the first study to examine the rotational deformity in the midfoot of CMT patients and, thus, provide key insights to successful correction of CMT cavovarus foot. Methods: A total of 27 WBCT scans from 21 CMT patients were compared to control WBCTs from 20 healthy unmatched adults. CMT patients with a history of bony surgery, severe degenerative joint disease, or open physes in the foot were excluded. Scans were analyzed using 3-dimensional software. Anatomic alignment of the tarsal bones was calculated relative to the anterior-posterior axis of the tibial plafond in the axial plane, and weightbearing surface in the coronal plane. Results: Maximal rotational deformity in CMT patients occurred at the transverse tarsal joints, averaging 61 degrees of external rotation (supination), compared to 34 degrees among controls ( P < .01). The talonavicular joint was also the site of peak adduction deformity in the midfoot, with an average talonavicular coverage angle measuring 12 degrees compared with −11 degrees in controls ( P < .01). Conclusion: This 3-dimensional WBCT analysis is the first to isolate and quantify the multiplanar rotational deformity in the midfoot of CMT patients. Compared with healthy unmatched control cases, CMT patients demonstrated increased axial plane adduction and coronal plane rotation at the talonavicular (TN) joint. These findings support performing soft tissue release at the TN joint to abduct and derotate the midfoot as a first step for targeted deformity correction. Level of Evidence: Level III, retrospective case-control study.

Effects of the Ankle Flexion Angle During Anterior Talofibular Ligament Reconstruction on Ankle Kinematics, Laxity, and In Situ Forces of the Reconstructed Graft

Background: This study aimed to evaluate the effects of the ankle flexion angle during anterior talofibular ligament (ATFL) reconstruction on ankle kinematics, laxity, and in situ force of a graft. Methods: Twelve cadaveric ankles were evaluated using a 6–degrees of freedom robotic system to apply passive plantar flexion and dorsiflexion motions and multidirectional loads. A repeated measures experiment was designed using the intact ATFL, transected ATFL, and reconstructed ATFL. During ATFL reconstruction (ATFLR), the graft was fixed at a neutral position (ATFLR 0 degrees), 15 degrees of plantar flexion (ATFLR PF15 degrees), and 30 degrees of plantar flexion (ATFLR PF30 degrees) with a constant initial tension of 10 N. The 3-dimensional path and reconstructed graft tension were simultaneously recorded, and the in situ force of the ATFL and reconstructed grafts were calculated using the principle of superposition. Results: The in situ forces of the reconstructed grafts in ATFLR 0 degrees and ATFLR PF 15 degrees were significantly higher than those of intact ankles. The ankle kinematics and laxity produced by ATFLR PF 30 degrees were not significantly different from those of intact ankles. The in situ force on the ATFL was 19.0 N at 30 degrees of plantar flexion. In situ forces of 41.0, 33.7, and 21.9 N were observed at 30 degrees of plantar flexion in ATFLR 0, 15, and 30 degrees, respectively. Conclusion: ATFL reconstruction with the peroneus longus (PL) tendon was performed with the graft at 30 degrees of plantar flexion resulted in ankle kinematics, laxity, and in situ forces similar to those of intact ankles. ATFL reconstructions performed with the graft fixed at 0 and 15 degrees of the plantar flexion resulted in higher in situ forces on the reconstructed graft. Clinical Relevance: Fixing the ATFL tendon graft at 30 degrees of plantar flexion results in an in situ force closest to that of an intact ankle and avoids the excessive tension on the reconstructed graft.

Vitamin D Deficiency and Outcomes After Ankle Fusion: A Short Report

Background: Vitamin D deficiency has been postulated as a cause for impaired bone healing and remodeling. The purpose of this study was to assess the potential association between low vitamin D levels and reoperation for nonunion following ankle fusion surgery. Methods: All adult patients (aged ≥18 years) who underwent ankle fusion procedures at a tertiary referral center from January 2010 to January 2019 with available vitamin D levels within 12 months preoperatively were retrospectively reviewed (n = 47). Patients were categorized as vitamin D deficient (<30 ng/mL) vs normal (31-80 ng/mL). The primary outcome was the incidence of reoperation secondary to nonunion. Secondary outcomes included incidence of reoperation not related to nonunion and the need for repeat reoperation. Results: The average level in the vitamin D–deficient group (n = 17; 36.2%) was 16.9 vs 46.4 ng/mL in the normal group (n = 30; 63.8%). All recorded reoperations for nonunion occurred exclusively in the vitamin D–deficient cohort (4/17 [23.5%]; P = .013). There were similar reoperation rates for causes other than nonunion (2/17 [11.8%] vs 4/30 [13.3%]; P > .99) and repeat reoperation rates (3/17 [17.6%] vs 1/30 [3.3%]; P = .128) among vitamin D–deficient vs normal patients. Conclusion: Vitamin D deficiency may be associated with an increased risk of reoperation for nonunion after ankle fusion.

Osteochondral Lesions of the Tibial Plafond and Ankle Instability With Ankle Cartilage Lesions: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle

Background: An international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to present the consensus statements on osteochondral lesions of the tibial plafond (OLTP) and on ankle instability with ankle cartilage lesions developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. Methods: Forty-three experts in cartilage repair of the ankle were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 4 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held. Results: A total of 11 statements on OLTP reached consensus. Four achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). A total of 8 statements on ankle instability with ankle cartilage lesions reached consensus during the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support, and seven reached strong consensus (greater than 75% agreement). Conclusions: These consensus statements may assist clinicians in the management of these difficult clinical pathologies. Level of Evidence: Level V, mechanism-based reasoning.

Screws-Only Primary Subtalar Arthrodesis for Calcaneus Fractures

Background: The management of displaced intraarticular calcaneus fractures (DIACFs) is a difficult problem with disappointing results from open reduction internal fixation (ORIF). Alternatively, ORIF with primary subtalar arthrodesis (PSTA) has gained increasing popularity. The purpose of this study is to review patient-centered and radiographic outcomes of ORIF plus PSTA using only screws through a sinus tarsi approach. Methods: A retrospective study of patients who underwent ORIF+PSTA for DIACFs was conducted. The same surgical technique was used in all cases consisting of only screws; no plates were used. Delayed surgeries past 8 weeks were excluded. Demographic and radiographic data were collected including worker’s compensation claims. Plain radiographs were used to characterize injuries and review outcomes. Results: Seventy-nine DIACFs underwent PSTA with a median follow-up of 200 days (n = 69 patients). Median time to weightbearing was 57.5 days postoperatively. Ten fractures were documented as Sanders II, 36 as Sanders III, and 32 as Sanders IV. Sixty-eight fractures (86.1%) achieved fusion on radiographs at a median of 126.5 (range, 54-518) days. Thirty-nine fractures (57.3%) demonstrated radiographic fusion in all 3 predefined locations. Nine of the 14 worker’s compensation patients returned to work within the period of observation. There were 8 complications: 3 requiring a secondary operation. Eleven of 79 fractures treated did not go on to achieve radiographic union. Conclusion: In this retrospective case series, we found that screws-only primary subtalar arthrodesis for the treatment of DIACFs through a sinus tarsi approach was associated with relatively high rates of return to work and radiographic fusion. Level of Evidence: Level IV, retrospective case series.

Fibula Nail Outcomes in Soft Tissue Compromised Ankle Fractures

Background: To determine the clinical outcomes following fibula nail fixation and to identify the indication for the use of fibula nails in lower limb fractures. Methods: Retrospective study of adult patients from 2 major trauma centers (MTCs) and 9 trauma units (TUs) who underwent fibula nail fixation for AO/OTA 44 fractures between January 1, 2018, and October 31, 2020. Outcome measures included infection, metalwork complications, nonunion or malunion, time to union, and length of inpatient hospital stay. Results: Ninety-five patients were included, with a mean age of 66 years; 57.9% of patients were female. The average body mass index was 30. Sixty-nine patients (72.6%) sustained a Weber B and 24 (27.4%) sustained a Weber C fracture. In addition, 26.3% were open fractures and all patients had soft tissue compromise affecting the lateral malleolus. The calculated infection rate for fibula nail was 4.2% and metalwork complication rate was 5.2%. The nonunion and malunion rate was 8.4% and rate of removal of hardware was 2.1%. The average time to union was 12.5 weeks, and length of inpatient stay was 9.4 days (SD 10). Conclusion: This multicenter study demonstrates that use of a fibula nail appears to be a safe approach to treating patients who have a physiologically higher risk of surgery, poor skin condition, and a complex fracture pattern.