The medial epicondyle-ulnar nerve relation with various elbow positions in healthy children.

BACKGROUND: The position of the ulnar nerve relative to the medial epicondyle in healthy children was determined with a high-resolution ultrasonography with elbow flexion, forearm pronation, and supination maneuvers which are commonly employed during reduction of the supracondylar humerus fractures. METHODS: Healthy children aged between 4 and 12 years were enrolled in this study. Both elbows of the children were evaluated with a high-resolution sonography device with gradual flexion of the elbow, whereas the forearm is alternately in pronation and supination. The medial epicondyle-ulnar nerve distance was measured with the various positions of the elbow and the forearm. One-way analysis of variance was used to analyze the differences of medial epicondyle-ulnar nerve distance at different elbow flexion angles and forearm supination-pronation positions. Paried t test was used to compare the differences between the age and sex of the children. RESULTS: Twelve female and 26 male children (76 elbows) with a mean age of 8.36 years were included in the study. Ulnar nerve was translated anteriorly through the medial epicondyle with increasing elbow flexion. The mean medial epicondyle-ulnar nerve distance that was 3.7 mm in an extended elbow decreased to 1.1 mm with full elbow flexion. The difference was statistically significant (P<0.0001). Presence of the forearm in either supination or pronation did not produce a statistically significant difference. The age and sex of the children did not produce a statistically significance difference in medial epicondyle-ulnar nerve distance. CONCLUSIONS: Flexion of the elbow brings the ulnar nerve to a close proximity to the medial epicondyle independent of forearm pronation and supination in healthy children. The decrement of the medial epicondyle-ulnar nerve distance up to 1.1 mm in a fully flexed elbow might be a factor that endangers the nerve during medial pinning in supracondylar humerus fractures. LEVEL OF EVIDENCE: Level I-diagnostic studies.

Comparison of proximal junctional kyphosis rate according to fusion level.

INTRODUCTION: There are two main accepted reasons of Proximal junctional kyphosis (PJK) after Scheuermann's kyphosis treatment; overcorrection of initial curve and fusion that is too short proximally. The purpose of this study was to evaluate the incidence of PJK in patients who have been previously treated for Schuermann's kyphosis with a curve exceeding 70° and corrected under 40° according to proximal fusion level T2 or T3. METHODS: We retrospectively evaluated 30 patients treated for Schuermann's kyphosis with single stage posterior only procedure. We included patients that we achieved at least 50% correction of the initial curve. The surgeries were performed at the same institution by a single senior spinal surgeon. Patients were divided into two groups according to proximal fusion level T2 (16 patients) or T3 (14 patients) and evaluated for PJK, follow-ups ended three years after surgery. RESULTS: Mean age was 22.7 in T2 and 21.6 years in T3 group. Mean preoperative Cobb angle was 78° in T2 and 78.7° in T3 group. The mean postoperative Cobb angle was 33.2° in T2 and 35° in T3 group. None of the patients showed neurologic complications. Four patients had PJK in T3 group and one needed revision. CONCLUSIONS: Selecting T2 as the proximal fusion level in Schuermann's kyphosis may decrease the incidence of PKJ. Studies with a larger number of patients needed to verify our results.

Do Magnetically Controlled Growing Rods Stimulate Longitudinal Vertebral Growth in Early-Onset Scoliosis Patients?

OBJECTIVE: Distraction-based systems are the most common systems used in the treatment of early-onset scoliosis. In addition to its corrective and deformity progression preventive properties, its vertebral growth stimulation effect has been proved. Recently popularized magnetically controlled growing rods (MCGRs) showed superior results in terms of outcomes and decreased complication rate. Its vertebral growth stimulation effect has not been studied. The aim of the study is to evaluate the vertebral growth stimulation effect in patients treated with MCGR. METHODS: Patients with progressive scoliosis treated by dual MCGR, who had no obvious lumbar vertebral deformity and had a regular 3-month interval spinal lengthening for at least 30 months, were subdivided into 2 groups according to the inclusion of L3 vertebra within instrumentation segments. The L3 vertebral vertical and horizontal lengths were measured postoperatively and at the last follow-up, and their differences were analyzed statistically in both groups. RESULTS: Twenty-four patients were included; 18 of them had an L3 vertebra outside instrumentation segments, while the other 6 had spanned by MCGR. Uninstrumented L3 were followed up for an average of 36 months. The height difference between initial postoperative examination and the last follow-up was 3.55 mm ± 0.63 mm, and the width difference was 3.85 mm ± 0.75 mm. Conversely, patients with instrumented L3 were followed up for a mean of 38.9 months. Their initial postoperative examination and last follow-up differences in height and width were 6.91 mm ± 1.11 mm and 3.66 mm ± 0.92 mm, respectively. CONCLUSIONS: Frequent distractions stimulate longitudinal vertebral growth in vertebrae spanned by MCGR.

Mid-length Pedicle Screws in Posterior Instrumentation of Scoliosis.

Study Design: Prospective analysis of collected data. Purpose: We determine the need for the use of mid-length pedicle screws (screws with 2.5-mm long increments) during posterior spinal instrumentation. Overview of Literature: Many biomechanical studies have been performed showing that increasing the pedicle screw insertion depth provides an improved resistance to pullout, cyclic loading, and derotational forces, but no intermediate length screws were used. Methods: We prospectively evaluated 120 patients who received posterior segmental instrumentation for structural scoliosis. Preoperatively, 91.44-cm long cassette anteroposterior (AP), lateral, and AP bending radiographs and multiplanar computed tomography were performed in all patients routinely. We measured chord length to determine the maximum probable screw length of all vertebrae. All pedicle screws were attempted to be placed as long as possible. The main intention was at least to engage the subcortical bone of the anterior vertebral cortex. Especially in the apical region, the screws were attempted to be inserted bicortically. The length, level, region, and side of each screw were recorded. Screws with 5-mm increments were called standard length screws (SLS), and middle-sized screws with 2.5-mm increments were called mid-length screws (MLS). Results: Of 2,846 pedicle screws inserted, 1,575 (55.4%) were SLS and 1,271 (44.6%) were MLS, demonstrating a need for MLS in scoliosis surgery (p <0.05). The need for MLS increased significantly in the thoracic region, apical vertebrae, and convex side (p <0.05). Conclusions: If anterior cortex engagement or longer placement of pedicle screws is intended during scoliosis surgery, for safer placement, screws with 2.5-mm increments should be available in posterior instrumentation systems.

A review of literature: Mosaicoplasty as an alternative treatment for resection of patellar osteoid osteoma and cartilage reconstruction.

Osteoid osteoma is an uncommon benign tumor and causes severe pain, being worse at night, that responds dramatically to nonsteroidal anti-inflammatory medications. An osteoid osteoma of the patella is very rare and if it arise close to chondral surface differential diagnosis may be challenging. In three patients the osteoid osteoma was completely excised by nidus removal by mosaicoplasty set with open surgical technique. The patients were followed up in average for 31 (16-48 months) months with annual clinical and radiographic evaluations. There were no relapse of the pain and no residual recurrent tumor. The aim of the treatment for osteoid osteoma is to remove entire nidus by open surgical excision or by percutaneous procedures such as percutaneous radiofrequency and laser ablation. Mosaicoplasty is a good alternative for treatment of osteoid osteoma of the patella in the subchondral bone.

Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model.

STUDY DESIGN: Mechanical study. PURPOSE: To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. OVERVIEW OF LITERATURE: Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone-screw interface. METHODS: Polyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve. RESULTS: The peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation. CONCLUSIONS: Expandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.

Do timing of injection and status of the suction drain effect postoperative pain scores after intra-articular bupivacaine injection in arthroscopic ACL reconstruction?

OBJECTIVE: The aim of this study was to determine if the timing of intra-articular local anesthetic injection and the status of the suction drain affect variable pain scores after ACL reconstruction. METHODS: The study included 40 patients undergoing arthroscopic ACL reconstruction randomized into 4 groups. Patients in Group 1 received intra-articular 20 ml of 0.25% bupivacaine 20 minutes before the start of the operation (preemptive: PE), Group 2 at the end of the operation with the suction drain opened (DO). Group 3 also received intra-articular bupivacaine at the end of the operation and the drain was kept closed for one hour postoperatively (DC). Group 4 did not receive any intra-articular injection (control group: CG) and served as the control group. Visual analog scale (VAS) scores and additional analgesic requirements were recorded. RESULTS: The PE group had the lowest and the control group the highest VAS scores at the second postoperative hour. At the fourth postoperative hour, VAS scores were significantly higher in the DC group than the DO group (p<0.05). At the sixth postoperative hour, the PE and DC groups had significantly lower VAS scores than the other groups (p<0.05). At Hour 12, the PE and control groups had higher VAS scores than the DO and DC groups. VAS scores were not different among groups at Hour 24. The interval to first analgesic requirement was significantly shorter in the control group and longer in the PE group in comparison to the other two groups (p<0.001). CONCLUSION: Intra-articular bupivacaine injection at different stages of the operation yielded variable VAS scores in the postoperative period. Closing the drain after intra-articular injection resulted in an early onset analgesic effect without shortening the duration.