Kayoko Furukawa

EXTENSOR POLLICIS LONGUS TENDON RUPTURES AFTER THE USE OF VOLAR LOCKING PLATES FOR DISTAL RADIUS FRACTURES

Currently, volar locking plates are commonly used to treat distal radius fractures (DRF) because of their stable biomechanical construct and because they cause less soft tissue disturbance and allow early mobilisation of the wrist. Complications such as rupture of tendons have been reported to occur with use of volar locking plates. We describe six cases of rupture of extensor pollicis longus (EPL) tendons after the use of volar locking plates. EPL tendon injuries occurred in 2.1% (6/286) of cases after DRF surgery. The causes of EPL rupture after DRF surgery were protrusion of the head tip and insufficient reduction of the dorsal roof fragment of the distal radius. These were considered iatrogenic problems. The cause of EPL rupture was unknown in three cases. We should be extremely careful when determining optimum screw length and reducing displaced dorsal roof fragments to prevent damaging the EPL tendons.

LINBURG-COMSTOCK SYNDROME: A CASE REPORT

We report a case of Linburg-Comstock syndrome, which is characterized with anomalous tendon slips connecting flexor pollicis longus (FPL) to the flexor digitorum profundus (FDP), usually at the index finger. The present patient started to be a carpenter and was suffering from his disability of flexing the thumb and the index finger independently when he handled the screws in his work. We surgically removed the tendinous connection of the FPL tendon and the index FDP tendon. After surgery, he could work as a carpenter without any difficulty. Surgical disconnection was effective treatment. Dynamic high-resolution ultrasound and three dimensions of computed tomography of the left distal forearm were helpful to confirm the diagnosis.

Elcatonin prevents bone loss caused by skeletal unloading by inhibiting preosteoclast fusion through the unloading-induced high expression of calcitonin receptors in bone marrow cells

This study aimed to clarify whether elcatonin (EL) has a preventive action on bone dynamics in skeletal unloading. Seven-week-old male C57BL/6J mice with either ground control (GC) or tail suspension (TS) were administered EL 20U/kg or a vehicle (veh) three times per week and assigned to one of the following four groups: GCEL, GCveh, TSEL, and TSveh. Blood samples and bilateral femurs and tibias of the mice were obtained for analysis. After 7days of unloading, the trabecular bone mineral density in the distal femur obtained via peripheral quantitative computed tomography and the trabecular bone volume were significantly higher in the TSEL group than in the TSveh group. The bone resorption histomorphometric parameters, such as the osteoclast surface and osteoclast number, were significantly suppressed in the TSEL mice, whereas the number of preosteoclasts was significantly increased. The plasma level of tartrate-resistant acid phosphatase-5b (TRACP-5b) was significantly lower in the TSEL group than in all other groups. In the bone marrow cell culture, the number of TRACP-positive (TRACP(+)) multinucleated cells was significantly lower in the TSEL mice than in the TSveh mice, whereas the number of TRACP(+) mononucleated cells was higher in the TSEL mice. On day 4, the expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), cathepsin K and d2 isoform of vacuolar ATPase V0 domain (ATP6V0D2) mRNA in the bone marrow cells in the TSEL mice was suppressed, and the expression of calcitonin receptor (Calcr) mRNA on day 1 and Calcr antigen on day 4 were significantly higher in the TSveh mice than in the GCveh mice. EL prevented the unloading-induced bone loss associated with the high expression of Calcr in the bone marrow cells of mouse hindlimbs after tail suspension, and it suppressed osteoclast development from preosteoclasts to mature osteoclasts through bone-resorbing activity. This study of EL-treated unloaded mice provides the first in vivo evidence of a physiological role of EL in the inhibition of the differentiation process from preosteoclasts to osteoclasts.

Post-traumatic malunion of the distal radial intra-articular fractures treated with autologous costal osteochondral grafts and bioabsorbable plates.

Intra-articular distal radial fractures with partial bone loss at the wrist were reconstructed using osteochondral grafts in 2 patients who were followed up for at least 18 months. Both patients experienced posttraumatic arthrosis of the wrist joint. The materials of the intra-articular fixation were bioabsorbable plates and screws. Reconstruction of a partially destroyed articular surface using a costal osteochondral graft is reliable and allows filling and resurfacing an articular cartilage void.

Correlation of Albumin/Globulin Ratio With Forearm Bone Mineral Density in Women Above 50 Years of Age

Objective: We aimed to determine whether blood test values correlate with bone mineral density by body part. Participants and Methods: We included data on 78 forearms of 78 women, aged 50 or older, treated for distal radius fracture at our hospital from October 2007 to October 2012. All underwent DXA (dual-energy x-ray absorptiometry) scan of the second to fourth lumbar vertebrae, femoral neck, and forearm bone (divided into 3 parts: ultra-distal [UD], mid-distal [MD], and proximal shaft [shaft]). The following blood test values were determined: ALB (albumin), A/G (albumin/globulin) ratio, AST (aspartame aminotransferase), ALT (alanin aminotransferase), LDH (lactate dehydrogenase), ALP (alkaline phosphatase), GTP (gamma-glutamyl transferase), Ca (calcium), P (phosphorus), BUN (blood urea nitrogen), Crea (creatinine), eGFR (estimated glomerular filtration rate), WBC (white blood cell), Hb (hemoglobin), Hct (hematocrit), and PT-INR (international normalized ratio of prothrombin time). Statistical Analysis: Using Pearson product-moment correlation coefficients, we analyzed the DXA scan results (lumbar vertebrae, femur, and 3 forearm parts) for correlations with age, height, weight, body mass index (BMI), and blood test values. Results: ALB, A/G ratio, LDH, Hb, and PT-INR correlated positively with bone mineral densities of the forearm (UD, MD, and shaft) and femur (neck), but not with those of the lumbar vertebrae. TP (total protein), AST, ALT, γGTP (γ-Glutamyltranspeptidase), P, BUN, Crea, eGFR, WBC, Hb, and Hct did not correlate with any bone mineral density values. Discussion: The A/G ratio had a stronger correlation with the bone mineral density of the proximal shaft (0.39), which has a high percentage of cortical bone than with those of MD (0.38) and UD (0.26). The A/G ratio also correlated with femoral neck bone mineral density (0.23), but not with those of the lumbar vertebrae. Our results thus suggest a correlation between cortical bone amount and albumin metabolism. Conclusions: Our statistical analyses identified correlations between blood test values and bone mineral density by body part in middle-aged and elderly females with distal radius fracture. Serum albumin and the A/G ratio correlated positively with forearm and femoral neck bone mineral densities, but not with lumbar vertebrae bone mineral densities. From the resultant value, albumin 3.3g/dL or A/G ratio 0.96 is equivalent to −2.5 SD in DXA. Serum albumin and AJG ratio can be a surrogate marker for screening osteoporosis.

Mechanical Properties and Clinical Results of Novel Bioabsorbable Plates for the Treatment of the Hand Fractures

Objective: The use of bioabsorbable implants that would negate the need for subsequent removal could offer major clinical advantages for the fixation of fractures. However, previous bioabsorbable plates have had several issues with regard to clinical usage. The aims of this study were to compare the mechanical properties of novel bioabsorbable plates with those of titanium plates in a fracture model and to demonstrate the clinical results of these new plates for hand fractures. Materials and Methods: The first set of experiments compared the mechanical properties of bioabsorbable and titanium plates. Two types of bioabsorbable plates made of hydroxyapatite/poly-L-lactide (1/3- and 1/2-circle in cross-section) and two types of titanium plates (for 1.5- and 2.0-mm screws) were tested. Each plate was fixed on a polyether ether ketone (PEEK) rod, which was transversely cut at its midsection. The second part of the studies demonstrated the clinical results of bioabsorbable plates used in 62 cases of 70 hand fractures including 39 metacarpal, 20 distal ulna, 5 distal radius, and 6 radial head fractures since July 2008. The mean age of the patients was 48.4 years (range, 13-89). The follow-up period ranged from 3 month to 4 years 9 months. Results: The bending strength and stiffness of 1/3-circle bioabsorbable plate constructs were comparable with those of titanium plates for 1.5-mm screws, and those of 1/2-circle bioabsorbable plates were comparable with those of titanium plates for 2.0-mm screws. The torsional strength of 1/2-circle bioabsorbable plates (mean ± standard deviation: 79.0 ± 7.9 N⋅cm) was significantly greater than that of titanium plates for 2.0-mm screws (56.7 ± 4.0 N⋅cm; P < .05). The nonunion rate was 2.9% (2 cases in radial head fractures/70 cases). About 4.3% (3/70 cases) was necessary for implant removal because of loose screws in 2 cases of metacarpal fractures and limited range of motion in 1 case of radial head fracture. For the consecutive cases with metacarpal fractures, there were no significant differences in 6-month postoperative clinical results between patients receiving bioabsorbable plates after July 2008 and titanium plates before July 2008 (267.0 ± 6.0 vs 250.0 ± 28.3 degrees of total range of active motion, and 92.7 ± 19.7 vs 86.4 ± 28.6% of contralateral grip strength). Conclusions: The bending strength, stiffness, and torsional strength of novel 1/3- or 1/2-circle bioabsorbable plates, when fixed on a PEEK rod, were comparable with those for titanium plates for 1.5- or 2.0-mm screws. The clinical study of bioabsorbable plates used in hand fractures revealed satisfactory results for union rate, range of motion, and grip strength. For metacarpal fractures, there were no significant differences in clinical results between bioabsorbable and titanium plates.

A Study of Conservative Treatment for Colles’ Fractures Using the Novel Classification by Lateral Radiographic View

Objective: The objective of this study is to elucidate the changes in radiographic parameters over time in conservative treatment of Colles’ fractures. Participants and Methods: The participants were 60 patients with Colles’ fractures (60 wrists) that were treated conservatively. They were l3 males and 47 females with a mean age of 72.5 years (range, 55-96 years). Based on the AO Foundation and Orthopaedic Trauma Association (AO/OTA) fracture and dislocation classification, the numbers of patients with type A2, A3, Cl, C2, and C3 fractures were 33, 5, 5, l2, and 5, respectively. The cause of injury was limited to a fall from eye height, and we excluded patients with a concurrent fracture of the distal ulnar metaphysis and patients with comminution of the palmar cortex. All the patients underwent manipulative reduction immediately after diagnosis. We focused on the palmar cortex in lateral radiographic views to classify the fractures into the intramedullary type, the anatomical type, and the extramedullary type, and measured the palmar tilt (PT), radial inclination (RI), and ulnar variance (UV) at the time of injury, immediately after reduction, and in final observation. Statistical Analysis: We analyzed the correction loss of PT, RI, and UV by Tukey-Kramer after one-way analysis of variance (ANOVA). Results: The fracture types immediately after reduction were the intramedullary type in 11 patients, the anatomical type in 42 patients, and the extramedullary type in 7 patients. The correction loss in PT and in RI was negative in each group, with no significant differences among the 3 groups, whereas UV was positive in each group. The correction loss was significantly greater in the intramedullary group than in the anatomical group and the extramedullary group. Conclusion: We analyzed radiographic parameter changes over time associated with reduced position in the conservative treatment of Colles’ fractures. The correction loss in UV immediately after reduction until the final observation was significantly greater in the intramedullary group than in the anatomical group and the extramedullary group.

Correlation Between Grip Strength and Forearm Bone Mineral Density in Women Over 60 Years of Age

Objective: Our objective was to determine whether grip strength correlates with bone mineral density by body part. Participants and Methods: We studied the data on 86 forearms of 86 women, aged 60 years or older, who had been treated for distal radius fractures at our hospital between October 2007 and October 2013. All the patients underwent DXA (dual-energy x-ray absorptiometry) scans of the second to fourth lumbar vertebrae, the femoral neck, and the forearm bone (divided into 3 parts: ultra-distal [UD], mid-distal [MD], and proximal shaft [shaft]). The grip strength of the hand on the noninjured side was examined twice, and we used the average of the results for analysis. Statistical Analysis: Using Pearson product-moment correlation coefficients, we analyzed the DXA scan results (lumbar vertebrae, femur, and 3 forearm parts) for correlations with age, height, weight, body mass index (BMI), and grip strength. Results: The grip strength on the noninjured side correlated positively with the bone mineral densities of the forearm (UD, MD, and shaft) and the femur (neck), but not with those of the lumbar vertebrae. Discussion: The grip strength on the noninjured side had a stronger correlation with the bone mineral density of the proximal shaft (0.351), which has a high percentage of cortical bone than with those of MD (0.340) and UD (0.338). It also correlated with the mineral density of the femoral neck bone (0.263), but not with that of the lumbar vertebrae. Our results suggest a correlation between cortical bone amount and noninjured side grip strength. Conclusions: Our statistical analyses revealed that grip strength on the noninjured side correlated positively with forearm and femoral neck bone mineral densities, but not with lumbar vertebrae bone mineral densities, in middle-aged and elderly females with distal radius fracture. The resultant values indicated that 12.0 kg of grip is equivalent to −2.5 SD in DXA. Grip strength on the noninjured side can be a surrogate marker for screening osteoporosis.