A Lateral Fracture Line Affects Femoral Trochanteric Fracture Instability and Swing Motion of the Intramedullary Nail: A Biomechanical Study.

Background: An unstable trochanteric femoral fracture is a serious injury, with a 1-year mortality rate of 5.4% to 24.9%, for which there is currently no standard treatment method. The lag screw insertion site is one of the primary contact areas between the cortical bone and an intramedullary nail. We hypothesized that a posterolateral fracture causes intramedullary nail instability when the posterolateral fracture line interferes with lag screw insertion. The purpose of the present study was to investigate the effect of posterolateral fracture line morphology on intramedullary nail stability by simulating unstable trochanteric femoral fractures with a posterolateral fracture fragment. Methods: Eighteen custom-made synthetic osteoporotic bone samples were used in the present study. Nine samples had a posterolateral fracture line interfering with the lag screw insertion hole (Fracture A), and the other 9 had a fracture line 10 mm away from the hole (Fracture B). Cyclic loading (750 N) was applied to the femoral head 1,500 times. Movement of the end cap attached to the intramedullary nail was recorded. The amplitudes of motion in the coronal plane (coronal swing motion), sagittal plane (sagittal swing motion), and axial plane (total swing motion) were evaluated. The change in the neck-shaft angle was evaluated on photographs that were made before and after the test. Medial cortical displacement was measured before and after the test. Results: Two Fracture-A samples were excluded because the amplitude of sagittal swing motion was too large. The mean values for coronal, sagittal, and total swing motion were 1.13 ± 0.28 mm and 0.51 ± 0.09 mm (p < 0.001), 0.50 ± 0.12 mm and 0.46 ± 0.09 mm (p = 0.46), and 1.24 ± 0.24 mm and 0.69 ± 0.11 mm (p < 0.001) for Fractures A and B, respectively. The mean neck-shaft angle change was -8.29° ± 2.69° and -3.56° ± 2.35° for Fractures A and B, respectively (p = 0.002). The mean displacement of the medial cortex was 0.38 ± 1.12 mm and 0.12 ± 0.37 mm for Fractures A and B, respectively (p = 0.57). Conclusions: This study showed that an unstable trochanteric femoral fracture with a posterolateral fracture line that interferes with the lag screw insertion holes is a risk factor for increased intramedullary nail instability.

Endosteal strut using a hydroxyapatite/poly-L-lactide mesh tube with a proximal humeral locking plate for the treatment of proximal humeral fractures.

PURPOSE: Proximal humeral fractures cause large intramedullary bone defects after humeral-head reduction. Hydroxyapatite/poly-L-lactide (HA/PLLA) materials are widely used for various fractures. However, the efficacy of endosteal strut using a HA/PLLA mesh tube (ES-HA/PLLA) with a locking plate for treating proximal humeral fractures was not reported. The purpose of this study is to examine the efficacy of ES-HA/PLLA with a proximal humeral locking plate in proximal humeral fractures. METHODS: Seventeen patients with proximal humeral fractures treated using ES-HA/PLLA with a locking plate from November 2017 to November 2021 were evaluated. The range of motion of the shoulder and postoperative complications were assessed at the final follow-up. Radiographs were evaluated to assess bone union and loss of reduction by measuring humeral-head height (HHH) and humeral neck-shaft angle (NSA). RESULTS: The average flexion and external rotation of the shoulder at the final follow-up were 137° (range, 90-180°) and 39° (range, - 10 to 60°), respectively. All fractures were united. The average HHH and NSA just after the surgery and final follow-up were 12.5 mm and 11.6 mm and 129.9° and 127.4°, respectively. Two patients presented screw perforation of the humeral head. One patient underwent implant removal due to infection. Avascular necrosis of the humeral head was observed in one patient with arthritis mutilans. CONCLUSIONS: The use of ES-HA/PLLA with a proximal humeral locking plate resulted in bone union in all patients and prevented postoperative loss of reduction. ES-HA/PLLA is one of the treatment options for proximal humeral fractures.

A biomechanical analysis of the effect of hydroxyapatite augmentation for trochanteric femoral fractures.

Hydroxyapatite (HA) augments are used to treat trochanteric femoral fractures. However, the efficacy of HA augmentation has not been fully described in trochanteric femoral fracture surgery. In total, 85 patients were enrolled in the present study; all had trochanteric femoral fractures between January 2016 and October 2020, 45 with HA (HA group) and 40 without HA (N group). The intraoperative lag screw insertion torque was directly measured and the amount of lag screw telescoping with and without HA augmentation after surgery was analyzed. Maximum lag screw insertion torque (max-torque), bone mineral density in the opposite femoral neck (n-BMD), tip apex distance (TAD) of the lag screw, radiographic findings including fracture union, the amounts of lag screw telescoping and occurrence of complications were evaluated. A total of 12 patients were excluded if they were aged under 60 years old, had ipsilateral surgery and disorders in the hip joint, TAD of the lag screw ≥26 mm on postoperative radiographs and had measurement errors. A total of 73 fractures could be analyzed: HA group (n=36) and N group (n=37). Max-torque/n-BMD ratios were higher in the HA group compared with in the N group (7.23±2.71 vs. 5.93±1.91 g/cm2·N·m; P=0.04). The amounts of lag screw telescoping in the HA group were smaller compared with the N group (1.41±2.00 vs. 2.58±2.34; P=0.05). Evaluation of screw insertion torque showed maximum screw insertion torque correlated well with n-BMD in both groups, HA (R=0.57; P<0.01) and N group (R=0.64; P<0.01). No correlation was found between maximum screw insertion torque and TAD in both groups, HA (R=-0.10; P=0.62) and N group (R=0.02; P=0.93). All fractures were radiographically united without any complications. These results support the effectiveness of HA augmentation, indicating higher resistance against rotational instability and reduced lag screw telescoping in trochanteric femoral fracture treatment.

Fixation of intra-articular calcaneal fractures: A comparative study of the postoperative outcome between HA/PPLA screws and locking plates.

Background: Forged unsintered hydroxyapatite and poly l-lactic acid (F-u-HA/PLLA) screw is bioactivite, bioabsorbable, and radiopaque with high mechanical strength. Its efficacy has been previously demonstrated in the treatment of lateral humeral condylar, lateral tibial condylar, ankle, and patellar fractures. However, studies on its efficacy in treatment of calcaneal fractures is lacking. This study aimed to compare the postoperative results of F-u-HA/PLLA screw fixation and locking plate fixation for intra-articular calcaneal fractures. Methods: From January 2013 to December 2019, 47 closed intra-articular fractures treated with either F-u-HA/PLLA screws (group S, 18 feet in 17 patients) or locking plates (group P, 29 feet in 28 patients) in a single trauma center were retrospectively reviewed. The sinus tarsi approach was used in both groups. The time to bone union, step-off, varus deformity, Bohler's angle, and width and height of the calcaneus were assessed after surgery. Ankle joint range of motion (ROM) and postoperative complications were also assessed. Results: All fractures were successfully treated. The Kaplan-Meier curves of the two groups showed similar trends. The log-rank test showed no significant difference in the time to bone union between the two groups (p = 0.48). In the Cox proportional hazards model adjusted for preoperative width and Bohler's angle, the hazard ratio for bone union was not statistically significant (HR: 1.13, 95%CI: 0.50-2.56, p = 0.78). Other variables included step-off (group S: 2.0 vs group P: 2.2 mm, p = 0.84), varus deformity (2.0° vs. 3.0°, p = 0.7), Gissane's angle (103.5° vs 104.0°, p = 0.84), width (38.0 vs 34.8 mm, p = 0.12), height (42.1 vs 44.0 mm, p = 0.07), and ankle ROM degrees (dorsal flexion, 20.0° vs. 20.0°, p = 0.13; plantar flexion 40.0° vs 40.0°, p = 0.56), which were not significantly different between groups P and S. The Bohler's angle was smaller in group S than in group P (20.5° vs 27.0°, p < 0.01). No skin necrosis or infection was observed in either group. Conclusion: Postoperative results of F-u-HA/PLLA screw fixation using the sinus tarsi approach for intra-articular calcaneal fractures were as good as those of locking plate fixation.

Pin and Wire System Fixation for the Treatment of Comminuted Patella Fractures.

We describe the wiring technique and evaluate the radiographic and clinical outcomes of treatment with a pin and wire system (PWS) for comminuted patella fractures. From June 2013 to October 2018, 33 patients with comminuted patella fractures were treated using a PWS. Open reduction and internal fixation was performed with multiple pins and a wire. All patients were allowed full weight bearing without a brace. Radiographs were obtained to evaluate bone union, implant breakage, back-out of pins, and intra-articular gaps and step-off. Clinical outcomes and postoperative complications were assessed at final follow-up examination. All fractures were united. Thirteen cable wires in 13 patients were partially broken without displacement of fracture at an average of 7.4 months (range, 1-19 months) postoperatively. The average preoperative, postoperative, and final follow-up intra-articular gap and step-off were 11.7 mm, 0.5 mm, and 0.03 mm and 6.6 mm, 0.4 mm, and 0.2 mm, respectively. The average postoperative pin displacement was 0.1 mm (range, 0-0.8 mm). Deep infection was not observed after the surgery. The implant removal rate was 21% (7 of 33). Among these, the symptomatic implant removal rate was 9% (3 of 33). Additionally, 3 of 7 patients with implant removal had broken wires. The average flexion and extension of knee joints were 139.7° (range, 120°-150°) and -0.9° (range, -10° to 0°), respectively. A PWS prevents back-out of the pins and reduces intra-articular gaps and step-off distances to acceptable levels, even if the cable wire is partially broken. Therefore, a PWS is a good treatment option for comminuted patella fractures. [Orthopedics. 2023;46(5):291-296.].

Effect of hydroxyapatite tubes on the lag screw intraoperative insertion torque for the treatment of intertrochanteric femoral fractures.

BACKGROUND: Hydroxyapatite (HA) augments are frequently used in orthopedic surgery. However, the effectiveness of HA augments on the treatment of intertrochanteric femoral fractures remains unknown. This study aimed to investigate whether the use of HA tubes affects the intraoperative insertion torque of the lag screw during intertrochanteric femoral fracture surgery. METHODS: From January 2016 to October 2020, 58 patients with intertrochanteric femoral fractures were included and divided into the HA treatment group (HA group, n = 29) and non-HA treatment group (N group, n = 29). Patients with intertrochanteric femoral fractures were treated using the Gamma3 nail system® with or without two HA tubes. HA tubes were inserted into the femoral head through the lag screw hole before the insertion of the lag screw. The mean and maximum intraoperative insertion torques of the lag screw, bone mineral density (BMD) of the uninjured opposite side femoral neck, and tip apex distance (TAD) of the lag screw on postoperative radiographs were assessed. To assess the loss of reduction after the surgery, we investigated the amounts of telescoping of the lag screw and the changes in the neck shaft angle. RESULTS: The mean and maximum insertion torques were correlated with BMD in the HA and N groups, respectively. The mean and maximum insertion torques were not correlated with TAD in the HA and N groups, respectively. The mean torque/BMD ratio was significantly higher in the HA group than in the N group (p = 0.03). There were no significant differences in the maximum torque/BMD ratio between HA and N groups (p = 0.06), while the maximum torque/BMD ratio tended to be higher in the HA group than in the N group. The amounts of telescoping of the lag screw in the HA group were significantly lower than that in the N group (p = 0.04), while there were no significant differences in the changes in the neck shaft angle between two groups (p = 0.32). CONCLUSION: Our results strongly suggest that the use of HA tubes increases the intraoperative lag screw insertion torque/BMD ratio and may improve the lag screw fixation by strengthening the bone/metal thread interface in the treatment of intertrochanteric femoral fractures.

Insidious Onset Compartment Syndrome of the Forearm in a Teenager: A Case Report and Review of the Literature.

Compartment syndrome affecting the upper extremities is a relatively underreported event compared with compartment syndrome affecting the lower extremities. Moreover, insidious onset forearm compartment syndrome has been rarely reported and is usually limited to single case reports. We report a compartment syndrome of the forearm in a teenager. She hit her right proximal forearm lightly on the cash register, but there was no pain. However, the next day, she had difficulty in moving her right hand. Although she underwent electrotherapy, her right forearm gradually became swollen, and she felt numbness in the ring and little fingers of her right hand. Six day after the onset, she came to our hospital and underwent fasciotomy. There was no aftereffect, and very good functional recovery was obtained. All clinicians need to keep the case of forearm compartment syndrome in a young individual with a diffuse course, such as in this case in mind.

Banding with lesser trochanter fragment using nonabsorbable tape in trochanteric femoral fractures.

INTRODUCTION: Trochanteric femoral fracture is one of the most common fractures in the elderly. Trochanteric femoral fracture with involvement of the lesser trochanter is considered unstable and recognized as having a poor prognosis. However, fixation of lesser trochanter fragment is scarce because of technical difficulties. In this study, we reported the simple surgical procedure and the effect of using nonabsorbable tape in lesser trochanter fixation. METHODS: From January 2014 to December 2017, 114 patients treated with proximal intramedullary nailing for trochanteric fractures with the lesser trochanter fragment were reviewed. Among patients enrolled in this study, 73 were followed up until radiographic bone union, of which 26 were treated with lesser trochanter fragment banding (group B) and 47 without banding (group N). Radiographs and/or computed tomography images were used to evaluate bone union of the lesser trochanter fragment at three months postoperatively. RESULTS: The bone union of the lesser trochanter fragment was achieved in 24 cases (92%) in group B and 30 cases (64%) in group N. Compared with group N, group B showed a significantly increased number of mild and moderate deformities but decreased number of severe deformity and nonunion (P < 0.001). Postoperative complications were not observed in both groups. CONCLUSIONS: From the viewpoint of increasing lesser trochanteric bone union ratio, fixation of the lesser trochanter fragment using nonabsorbable tape in the treatment of trochanteric fractures could be an effective procedure.

Pyogenic tenosynovitis of the wrist due to Corynebacterium striatum in a patient with dermatomyositis: A case report.

INTRODUCTION: Corynebacterium striatum is common contaminant in clinical specimens. Here, we report a rare case of pyogenic tenosynovitis of the wrist caused by C striatum in a dermatomyositis patient taking oral immunosuppressants. PATIENT CONCERNS: A 67-year-old Japanese woman with dermatomyositis had a history of multiple intraarticular injections of corticosteroids to the right wrist joint for the treatment of osteoarthritis. She was admitted to our hospital with a painful lump on the right dorsal wrist lasting for three months. MRI revealed cellulitis of the dorsum of the right wrist and hand and fluid collection in the extensor tendon sheath. C striatum was detected in the cultures of three samples of synovial fluid taken from the dorsal hand. DIAGNOSIS: Pyogenic tenosynovitis of the wrist due to C striatum. INTERVENTIONS: The infection was successfully controlled with synovectomy and adjuvant antibiotic therapy. OUTCOMES: There has been no sign of recurrence for 12-months after the surgical treatment. LESSONS: This is the first reported case of pyogenic tenosynovitis due to C striatum in a patient with dermatomyositis. Clinicians should be aware that patients undergoing immunosuppressive therapy have a risk of C striatum infection.