Bone mineral density, limb muscle mass, muscle strength, and exercise capacity are reduced in female patients with distal radius fractures when the unaffected side grip strength is less than 18 kg.

BACKGROUND: Prevention of domino effects after distal radius fractures is important for improving life expectancy. Fragility fractures secondary to falls are associated with decreased bone mineral density, muscle strength, and exercise capacity. Grip strength is one of the simplest and most useful tests to comprehensively judge muscle strength. The purpose of this study was to examine whether grip strength is associated with bone mineral density, limb muscle mass, muscle strength, and exercise capacity, by comparing patient backgrounds based on the presence or absence of grip weakness in female patients with distal radius fractures. METHODS: This study included women with distal radius fractures who visited our orthopedics outpatient department between April 2015 and April 2020. Bone mineral density, limb muscle mass, skeletal muscle mass index, muscle strength (grip strength on unaffected side and quadriceps muscle strength), the Timed Up and Go test, and the Two-Step test were evaluated six to eight weeks after injury. Patients were divided into two groups according to the cutoff value of grip strength (18-21 kg), and 90 age-adjusted and matched participants were compared and examined. RESULTS: At the cutoff value of 18 kg, a significant decrease in lumbar spine and total proximal femur bone mineral density (p < 0.05, p < 0.05), limb muscle mass and skeletal muscle mass index (p < 0.01, p < 0.05), quadriceps femoris muscle strength (p < 0.01), the Timed Up and Go test (p < 0.05), and the Two-Step test (p < 0.01), was observed in the grip-weakness group compared to that in the no-grip-weakness group. CONCLUSIONS: In women with distal radius fracture and grip strength <18 kg on the unaffected side, bone mineral density, limb muscle mass, quadriceps femoris strength, and exercise capacity may be reduced. These results suggest reduced grip strength may be an indicator for further testing to prevent domino effects.

Effect of difference in fixation methods of tendon graft and the microfracture procedure on tendon-bone junction healing.

BACKGROUND: There are generally two methods of fixation for tendon grafts used in ligament reconstruction: bone tunnel fixation and anchor fixation. The microfracture (Mf) procedure is a technique to induce bleeding from the bone marrow, and the bleeding may contain cells with differentiation potential. However, few studies have compared the effects of the Mf procedure with those of the fixation methods. This study aimed to evaluate the effectiveness of the Mf procedure on two tendon graft fixation methods: histological, gene expression, tendon graft thickness, and mechanical. We especially focused our investigation on junction healing of tendon grafts and bone in the two fixation methods. METHODS: We used 20 rabbits to evaluate tendon and bone healing in a peroneal tendon graft model. The rabbit models were divided into five groups according to the combination of peroneal tendon graft fixation method and Mf technique as follows: control group (C, n = 4), bone tunnel fixation without Mf procedure group (BT - Mf, n = 4), bone tunnel fixation with Mf procedure group (BT + Mf, n = 4), anchor fixation without Mf procedure group (A - Mf, n = 4), and anchor fixation with Mf procedure group (A + Mf, n = 4). All animals were sacrificed at 4 weeks postoperatively. The specimens underwent histological evaluation, mRNA analysis, tendon graft thickness at the tendon-bone junction, and biomechanical testing. RESULTS: Histological evaluation of the BT + Mf and A + Mf groups showed healing with fibrocartilage formation at the tendon graft-bone junction. The mRNA expression showed significant increase in type 2 collagen, Scleraxis, and SRY-box9 in the BT + Mf and A + Mf groups. In biomechanical tests, the BT + Mf and A + Mf groups showed significantly increased tensile strength compared with the BT - Mf and A - Mf groups (BT + Mf group, 21.6 ± 1.7 N; A + Mf group, 22.5 ± 2.3 N vs. BT - Mf group, 12.3 ± 2.4 N; A - Mf group, 11 ± 2.3 N). CONCLUSION: The Mf procedure resulted in fibrocartilage formation at the tendon-bone junction in the BT and anchor fixation and improved the fixation strength at 4 weeks.

Postoperative change in the length and extrusion of the medial meniscus after anterior cruciate ligament reconstruction.

PURPOSE: The medial meniscus is a secondary stabilizer of anterior tibial translation in anterior cruciate ligament (ACL)-deficient knees. ACL reconstruction effectively restores an increased anterior tibial translation in the ACL-deficient knee. However, knee osteoarthritis sometimes develops in ACL-reconstructed patients during a long-term follow-up period. We hypothesized that the medial meniscal position would be different between the ACL-deficient and reconstructed knees. The aim of this study was to investigate pre-operative and postoperative location of the medial meniscus in patients who underwent ACL reconstruction. METHODS: ACL-reconstructed knees (28 knees) and normal knees (27 knees) were investigated. Medial tibial plateau length (MTPL) and medial tibial plateau width (MTPW) were determined using radiographic images. Magnetic resonance imaging (MRI)-based medial meniscal length (MML), medial meniscal width (MMW), and medial meniscal extrusion (MME) were measured. Postoperative change in the MML, MMW, and MME were evaluated and compared with those in normal knees. RESULTS: No significant differences between the ACL-deficient (pre-operative) and normal groups were noted. The ACL-reconstructed (postoperative) group showed an increase in the MML, in the percentage of the MML (%MML = 100 MML/MTPL), and in the MME. Significant differences between postoperative and normal groups were observed in the MML, %MML, and MME. MMW and MMW percentage (100 MMW/MTPW) were similar in all groups. CONCLUSIONS: The anteroposterior length and radial extrusion of the medial meniscus increased after ACL reconstruction. Transposition of the medial meniscus may be a possible cause of developing further degenerative knee joint disorders after ACL reconstruction.