Low-Intensity Pulsed Ultrasound for Delayed Union of Distal Radius Fracture After Palmar Locking Plate Fixation: A Case Report.

Delayed union and non-union of distal radial fractures (DRFs) are rare, and there are a few reports of delayed union and nonunion of DRFs after palmar locking plate (PLP) fixation. A 68-year-old female patient presented to our hospital with left-sided wrist pain. Radiographs and computed tomography revealed a displaced DRF and ulnar styloid fracture. We performed open reduction and internal fixation with a PLP for the DRF and tension band wiring for the ulnar styloid fracture. However, bone union was not completed three months after the operation. We initiated low-intensity pulsed ultrasound (LIPUS) to achieve fracture healing. Complete bone union was confirmed radiographically five months after LIPUS. There have been few case reports on the delayed union or nonunion of DRFs after PLP fixation treated with LIPUS. LIPUS might be an effective option for the delayed union of DRFs after PLP fixation.

Japanese version of Patient-Rated Elbow Evaluation is a useful outcome measure that potentially reflects hand function in patients with rheumatoid arthritis who underwent total elbow arthroplasty.

OBJECTIVES: We examined the relationship between the Japanese version of Patient-Rated Elbow Evaluation (PREE-J) and other established subjective and objective outcome measures in Japanese patients with rheumatoid arthritis (RA) who underwent total elbow arthroplasty (TEA). MATERIALS AND METHODS: This study involved 46 elbows of 40 RA patients. We collected clinical data 1 year after surgery, including the PREE-J, the Mayo Elbow Performance Score (MEPS), Disability of the Arm, Shoulder, and Hand (DASH), and Hand20. The correlation and responsiveness to PREE-J were evaluated compared with other outcome measures preoperatively and postoperatively. RESULTS: Almost all outcome measures were improved significantly after surgery. Preoperative PREE-J was significantly correlated with preoperative DASH, Hand20, and MEPS. Interestingly, postoperative PREE-J did not correlate with postoperative MEPS. Multiple regression analyses revealed that preoperative grip strength [B = -0.09; 95% confidence interval (95% CI) -0.17 to -0.01, p = 0.03] and preoperative Hand20 (B = 0.31, 95% CI 0.03-0.58, p = 0.03) were significant factors that might influence the postoperative PREE-J. CONCLUSIONS: The PREE-J was shown to correlate well with other preoperative outcome measures among the RA patients included in the current study. The postoperative PREE-J after TEA was influenced by the preoperative grip strength and function of the hand.

Evaluation of anterior oblique ligament tension at the elbow joint angle-a cadaver study.

BACKGROUND: The ulnar collateral ligament complex, particularly the anterior oblique ligament (AOL), is mainly a static stabilizer controlling valgus. Various studies have been conducted on the kinematics of elbow joints after ligament cutting; however, no biomechanical studies have measured the tension applied to the ligament. Finite element modeling (FEM) is a very useful tool for biomechanical evaluation of the elbow. However, an accurate FEM of elbow joints cannot be developed without information on the potential tension of ligaments applied during the flexion and extension of elbow joints. We believe that FEM of the elbow joint could be obtained by measuring the material properties and potential tension of the ligament applied during the flexion and extension of the elbow joint. This study aimed to measure the potential tension and material properties of the ligament during the flexion and extension of the elbow, by identifying the relation between ligament length and tension using mechanical testing. METHODS: We included 10 elbows harvested from 7 fresh-frozen cadavers. The average age of the cadavers was 83.7 ± 5.65 years, and the samples included 8 elbows from 6 male cadavers and 2 elbows from 1 female cadaver. We measured the ligament length at each elbow angle by changing the elbow joint from 0° to 120° in 15° intervals. Thereafter, we extracted the AOL and divided into an anterior band (AB) and a posterior band (PB) and performed a mechanical test to calculate ligament stress. RESULTS: The ligament length of the AB gradually decreased as the flexion angle increased. Conversely, the ligament length of the PB gradually increased as the flexion angle increased. AB and PB lengths were approximately the same between 60° and 75°. The average ligament tension and stress of the AB gradually increased with elbow extension. In contrast, the average ligament tension and stress of the PB gradually increased with elbow flexion. The tension and stress of the AB and PB were balanced around the elbow joint at 60°. CONCLUSION: The AB was tenser on elbow extension, and the PB was tenser following elbow flexion. Also, the angle at which the AOL stress was equalized was 60°, suggesting that ∼60° is the angle at which the AOL is unlikely to be damaged.

Biomechanics of callus in the bone healing process, determined by specimen-specific finite element analysis.

As fractures heal, immature callus formed in the hematoma is calcified by osteoblasts and altered to mature bone. Although the bone strength in the fracture-healing process cannot be objectively measured in clinical settings, bone strength can be predicted by specimen-specific finite element modeling (FEM) of quantitative computed tomography (qCT) scans. FEM predictions of callus strength would enable an objective treatment plan. The present study establishes an equation that converts material properties to bone density and proposes a specimen-specific FEM. In 10 male New Zealand white rabbits, a 10-mm long bone defect was created in the center of the femur and fixed by an external fixator. The callus formed in the defect was extracted after 3-6 weeks, and formed into a (5 × 5 × 5 mm3) cube. The bone density measured by qCT was related to the Young's modulus and the yield stress measured with a mechanical tester. For validation, a 10-mm long bone defect was created in the central femurs of another six New Zealand white rabbits, and fixed by an external fixator. At 3, 4, and 5 weeks, the femur was removed and subjected to Computed tomography (CT) scanning and mechanical testing. A specimen-specific finite element model was created from the CT data. Finally, the bone strength was measured and compared with the experimental value. The bone mineral density σ was significantly and nonlinearly correlated with both the Young's modulus E and the yield stress σ. The material-property conversion equations were E = 0.2391e8.00ρ and ρ = 30.49σ2.41. Moreover, the experimental bone strength was significantly linearly correlated with the prospective FEM. We demonstrated the Young's moduli and yield stresses for different bone densities, enabling a FEM of the bone-healing process. An FEM based on these material properties is expected to yield objective clinical judgment criteria.

A1 pulley stretching treats trigger finger: A1 pulley luminal region under digital flexor tendon traction.

BACKGROUND: A1 pulley stretching is recognized as a clinically beneficial treatment for trigger finger. It is thought to lead to an increase in the cross-sectional area of the A1 pulley luminal region, thus improving trigger finger symptoms. The purpose of the present study was thus to evaluate the resultant forces during stretching that increase the CSA of the A1 pulley luminal region using fresh-frozen cadavers. METHODS: Using seven fingers from three fresh-frozen cadavers to replicate A1 pulley stretching, we investigated the resultant forces during stretching that increase the cross-sectional area of the A1 pulley luminal region. The traction forces of the flexor digitorum profundus tendons were increased in steps to 150 N, and the cross-sectional area and height of the A1 pulley luminal region were measured using ultrasonography. FINDINGS: The cross-sectional area of the A1 pulley luminal region increased with step-wise increases in the flexor digitorum profundus traction. On average, the cross-sectional area and height of the A1 pulley luminal region showed increases of 31.4% and 43.6%, respectively, compared to the unloaded condition. INTERPRETATION: These results confirmed that A1 pulley stretching increases the cross-sectional area of the A1 pulley luminal region. A1 pulley stretching has the potential to reduce the severity of trigger finger in patients facing surgery.

Fusion Surgery Required for Recurrent Pediatric Atlantoaxial Rotatory Fixation after Failure of Temporary Fixation with Instrumentation.

In cases of chronic irreducible and recurrent unstable atlantoaxial rotatory fixation (AARF), closed reduction and its maintenance are often unsuccessful, requiring surgical treatment. The purpose of the present report is to describe a rare case of pediatric AARF that required multiple treatments. A 6-year-old boy was diagnosed as having type 2 AARF. After conservative treatment, the patient was treated with temporary fixation surgery (C1-C2 Magerl) without a bone graft in consideration of motion preservation after screw removal. AARF recurred after the screw removal and required fusion surgery (Magerl-Brooks) with an iliac bone graft. Ultimately, bone union was achieved and the screws were removed 11 months after the surgery. We recommend surgeons be cautious when choosing temporary fixation surgery for AARF in small children. Further investigation is needed to determine the optimal time before screw removal.

Evaluation of behavior and expression of receptor activator of nuclear factor-kappa B ligand in dorsal root Ganglia after sciatic nerve compression and application of nucleus pulposus in rats.

STUDY DESIGN: Experimental animal study. PURPOSE: To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. OVERVIEW OF LITERATURE: The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats. METHODS: MECHANICAL HYPERALGESIA AND RANKL EXPRESSION WERE ASSESSED IN THREE GROUPS OF RATS: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry. RESULTS: Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01). CONCLUSIONS: The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP.

Characteristics of Postural Sway during Quiet Standing Before and After the Occurrence of Neurogenic Intermittent Claudication in Female Patients with Degenerative Lumbar Spinal Canal Stenosis.

[Purpose] This study investigated the effect of neurological symptoms and/or signs after the occurrence of neurogenic intermittent claudication (NC) on postural sway during quiet standing of patients with lumbar spinal canal stenosis (LSS). [Subjects and Methods] Thirty-two female patients with LSS at the L4/5 level were studied. We measured the path of center of foot pressure (COP) during quiet standing with eyes open for 30 s using a stabilometer before and after the occurrence of NC. [Results] The total path length of COP (LC) and area surrounded by the outline of the path of COP (AC) significantly increased after NC. Body mass index (BMI) correlated with both the NC rate (after NC/before NC) of LC and that of AC. The average lateral COP displacement from the center of the base of support (COPRL) before NC was located on the asymptomatic side from the center of the base of support in 29 of 32 patients. After NC, COPRL moved to the symptomatic side in 31 patients. [Conclusion] These results suggest that patients with LSS are at risk of falling after NC, especially those with high BMI.