Purpose: The treatment of fractures has shown excellent safety enabling solid fixation and early exercise treatment with the development of internal metal fixtures and fixation techniques. On the other hand, complications remain, such as secondary surgery for implant removal and, discomfort caused by internally fixed metal materials. Recently, a bioabsorbable magnesium implant with relatively high strength and low decomposition, manufactured using only body components, was developed in the form of screws and K-wire for use in orthopedic surgery. This study aimed to apply bioabsorbable magnesium screws and K-wires to upper extremity fracture surgery and investigate the results. Materials and Methods: From May 2019 to September 2019, 46 cases (clavicle 11, humerus 4, olecranon 2, radial head 4, coronoid process 3, radius 4, ulna 1, phalanx 8, metacarpals 8, and hamate 1) in 44 patients who agreed to use a bioabsorbable magnesium implant among patients requiring internal fixation using screws and K-wires for upper extremity fractures at the author’s orthopedic surgery department were enrolled. The U&I Corporation commissioned this study, and a prospective study was conducted. The radiological findings and The Disabilities of the Arm, Shoulder, and Hand (DASH) score, hydrogen gas generation, and complications were evaluated. In comminuted fractures, the magnesium screws and K-wires were used for additional interfragmentary fixation with a conventional metal plate and screws in 22 cases. There were 24 cases of exclusive usage. The most common surgical method was intramedullary fixation of bioabsorbable magnesium K-wires in 10 cases. Results: In all cases, bone union was achieved on average 16 weeks (4–28 weeks) after surgery, and the mean DASH score at the last follow-up was 45.0 (30–116). A hydrogen gas cavity produced around the absorbable magnesium implant was observed at an average of two weeks and six days, and the largest was noted at an average of 12 weeks. There were no interactive reactions with drugs, infection, osteolysis, tendon rupture and swelling with hydrogen gas. There were two cases of the loss of reduction, one case of implant breakage, two cases of urticaria. Conclusion Bioabsorbable magnesium screws and K-wires can be applied for upper extremity fractures, but caution is required.

Purpose: Varus thrust is an posterolateral rotatory knee motion observed with severe varus patients. It shows a dynamic worsening of varus in the loading response (LR), while returning to a more neutral alignment during the initial contact (IC) of gait. This study examined the results of primary total knee arthroplasty in varus thrust osteoarthritis, including varus thrust motion, gait analysis. Materials and Methods: From March 2009 to March 2019, among 2,391 total knee arthroplasty who underwent total knee arthroplasty, 84 knees from 68 patients with varus thrust and more than a 20° varus deformity were enrolled in this study. The pre-operative and postoperative varus thrust amount (VTA), proximal tibiofibular overlap (PTFOL), and implant position (α, β, γ, and δ) were examined. The gait pattern was analyzed before and after surgery using the footscan ® (RSscan International, Olen, Belgium), evaluating the foot axis-center of pressure angle (FCA) of the ipsilateral foot at the IC and at the LR. The clinical outcomes were evaluated with Hospital for special surgery (HSS). Results: The changes in the VTA were from a pre-operative mean of 5.1° (3.1–7.2) to a mean of 1.9° (0.3–2.8) at the last follow-up (p=0.017). PTFOL changed from pre-operative mean of 18.1 mm (9.0–29.1) to post-operative mean of 11.0 mm (4.2–20.7) (p=0.029). The mean α, β, γ, and δ angle in the last follow-up was 94.6°, 90.3°, 3.86°, and 89.7°, respectively. The FCA in IC was corrected from a pre-operative mean of -1.8° (-1.0 to -4.4) to a post-operative mean of 2.3° (-1.1 to 4.1) (p=0.013). FCA in LR was similar from a pre-operative mean of 5.2° (1.0–7.2) to a post-operative mean of 6.0° (1.1–7.4) (p=0.823). The HSS was changed from a pre-operative mean of 45.7 to a post-operative mean of 86.2 in the last follow-up (p=0.011). Conclusion Standard total knee arthroplasty in the varus thrust knee showed satisfactory correction of the varus thrust amount and gait pattern, without recurrence of the varus thrust gait. Better clinical results were achieved in total knee arthroplasty of osteoarthritis with a varus thrust without using a constraining implant.