Management of hangman's fractures and a subaxial compression fracture in two children with osteogenesis imperfecta.

Cervical spine fractures in osteogenesis imperfecta are rare. The purpose of this article is to describe the successful outcomes of the nonoperative and operative treatment of C2 pars fracture and operative treatment of C7 compression fracture in two children with osteogenesis imperfecta. Patient 1, a 22-month-old female, had a C2 pars fracture managed nonoperatively with a cervical orthosis. Patient 2, a 15-year-old male, had concurrent C2 pars and C7 compression fractures; the C2 pars fractures were treated operatively via a posterior approach and open reduction and internal fixation, and the C7 compression fracture was treated via a C7 corpectomy, iliac crest strut autograft, and anterior plating from C6 to T1. Patient 1 had delayed union but complete healing at latest follow-up (31 months postpresentation). At latest follow-up, patient 2 remained asymptomatic.

Elbow strength and endurance in patients with a ruptured distal biceps tendon.

BACKGROUND: Patients with complete distal biceps tendon ruptures complain of fatigability with repeated elbow flexion and forearm supination. Some studies have documented changes in strength, but limited information is available about the effects of biceps tendon rupture on endurance. HYPOTHESIS: A ruptured distal biceps tendon results in decreased strength and enducance. MATERIALS AND METHODS: Isokinetic strength and endurance in elbow flexion and forearm supination were measured in both arms of 9 patients with an untreated unilateral complete distal biceps tendon rupture. One additional patient underwent isokinetic testing only. Tests were conducted using a dynamometer at 60 degrees per second for isokinetic strength and 240 degrees per second for endurance. Paired t tests were used for statistical analysis. RESULTS: The peak torque was significantly lower in involved limbs for both flexion (involved, 26.5+/-11.1Nm; uninvolved, 41.0+/-12.6Nm, P < .001) and supination (involved, 4.5+/-2.4Nm; uninvolved, 8.3+/-2.9Nm; P < .001). No significant differences were found in the fatigue index between involved and uninvolved limbs for flexion (involved, 43.2+/-14.1; uninvolved, 45.9+/-13.5; P=.659) or supination (involved, 58+/-17.0; uninvolved, 54.3+/-14.8; P=.592). DISCUSSION: Complete rupture of the distal biceps tendon results in substantial reductions in elbow flexion and forearm supination strength. Endurance of the remaining intact musculotendinous units does not seem to increase or decrease over time. Nonoperative treatment is rarely recommended, but when selected, rehabilitation should concentrate on improving strength, not endurance. CONCLUSION: A ruptured distal biceps tendon results in a substantial decrease in flexion and supination strength.

Correlation of quality of life and functional outcome measures for cervical spondylotic myelopathy.

OBJECT: Studies comparing surgical treatments for cervical spondylotic myelopathy (CSM) are heterogeneous, using a variety of different quality of life (QOL) outcomes and myelopathy-specific measures. This study sought to evaluate the relationship of these measures to each other, and to better understand their use in evaluating patients with CSM. METHODS: A retrospective study was performed in all patients with CSM who underwent either ventral or dorsal cervical spine surgery at a single tertiary-care institution between January 2008 and July 2013. Severity of myelopathy was assessed pre- and postoperatively using both the Nurick scale and the modified Japanese Orthopaedic Association (mJOA) classification of disability. Prospectively collected QOL outcomes data included Pain Disability Questionnaire (PDQ), Patient Health Questionnaire-9 (PHQ-9), and EQ-5D. Spearman rank correlations were calculated to assess the construct convergent validity for each pair of health status measures (HSMs). To assess each HSM's ability to discriminate favorable EQ-5D index, we performed receiver operating characteristic (ROC) curve analysis and assessed the area under the curve (AUC). RESULTS: A total of 119 patients were included. The PDQ total score had the highest correlation with EQ-5D index (Spearman's rho = -0.82). Neither of the myelopathy scales (mJOA or Nurick) had strong correlations between themselves (0.41) or with the other QOL measures (absolute value range 0.13-0.49). In contrast, the QOL measures correlated relatively well with each other (absolute value range 0.68-0.97). For predicting favorable EQ-5D outcomes, PDQ total score had an AUC of 0.909. The AUCs were significantly greater for the QOL measures in comparison with the myelopathy measures (AUCs were 0.677 and 0.607 for mJOA and Nurick scale scores, respectively). CONCLUSIONS: The authors found that all included measures of QOL and CSM-specific (mJOA or Nurick scale) measures were valid and responsive. The PDQ was the most predictive of positive QOL after surgery (as measured by the EQ-5D index) for patients with CSM. The substantially lower correlation between myelopathy and QOL outcomes, compared with the various QOL measures themselves, suggests that these questionnaires are measuring different aspects of the patient experience. Solely assessing the myelopathy or disease-specific signs and symptoms is likely insufficient to fully understand and appreciate clinical outcome in its totality. These questionnaire types should be used together to best evaluate patients pre- and postoperatively.

Anterior cervical discectomy and fusion versus cervical disc arthroplasty: current state and trends in treatment for cervical disc pathology.

STUDY DESIGN: Epidemiologic study using national administrative data. OBJECTIVE: To compare anterior cervical discectomy and fusion (ACDF) with cervical disc arthroplasty (CDA) for the treatment of cervical disc pathology in terms of (1) patient and hospital characteristics, length of stay, and total charges; and (2) temporal changes in those variables and in overall numbers. SUMMARY OF BACKGROUND DATA: Studies have shown that CDA has results and safety profiles comparable with those of ACDF, but information on patient and hospital characteristics and economical impact of CDA is lacking. METHODS: We queried the Nationwide Inpatient Sample for all hospitalization records from 2005 through 2008 with International Classification of Diseases, Ninth Revision, Clinical Modification codes corresponding to ACDF or CDA, used multivariable linear regression analyses (significance, P, 0.05) for patient and hospital characteristics, and calculated length of stay parameters. For total hospital charges, we used the consumer price index to convert all charges to 2008 US dollars. RESULTS: Most of the 544,174 ACDF procedures occurred in the South; most of the 4,710 CDA procedures occurred in the West and South. Compared with patients undergoing ACDF, those undergoing CDA were younger (P, 0.001). Comorbid severity for ACDF increased over time (P, 0.001) but did not change for CDA (P = 0.664). Although hospital stay decreased for both groups, total hospital charges increased for ACDF but remained stable for CDA over time. CONCLUSION: Patients undergoing CDA tended to be younger and to have less comorbidity, shorter hospital stays, and lower costs. The number of CDAs increased over time, although the percentage remained relatively small in comparison with that for ACDF.

A computer-controlled near-field electrospinning setup and its graphic user interface for precision patterning of functional nanofibers on 2D and 3D substrates.

Electrospinning is a versatile technique for production of nanofibers. However, it lacks the precision and control necessary for fabrication of nanofiber-based devices. The positional control of the nanofiber placement can be dramatically improved using low-voltage near-field electrospinning (LV-NFES). LV-NFES allows nanofibers to be patterned on 2D and 3D substrates. However, use of NFES requires low working distance between the electrospinning nozzle and substrate, manual jet initiation, and precise substrate movement to control fiber deposition. Environmental factors such as humidity also need to be controlled. We developed a computer-controlled automation strategy for LV-NFES to improve performance and reliability. With this setup, the user is able to control the relevant sensor and actuator parameters through a custom graphic user interface application programmed on the C#.NET platform. The stage movement can be programmed as to achieve any desired nanofiber pattern and thickness. The nanofiber generation step is initiated through a software-controlled linear actuator. Parameter setting files can be saved into an Excel sheet and can be used subsequently in running multiple experiments. Each experiment is automatically video recorded and stamped with the pertinent real-time parameters. Humidity is controlled with ±3% accuracy through a feedback loop. Further improvements, such as real-time droplet size control for feed rate regulation are in progress.

New rabbit knee model of posttraumatic joint contracture: indirect capsular damage induces a severe contracture.

Reported models of joint contracture fail to result in severe motion loss. Our purpose was to develop a rabbit model of knee contracture and compare it to another well-accepted model to determine if more severe stiffness can be achieved. Sixteen skeletally mature New Zealand White female rabbits had their right knee operated to create 3-mm defects on the noncartilaginous portions of the femoral condyles, hyperextend the joint to disrupt the posterior capsule, and immobilize the joint in maximum flexion with a Kirschner-wire for 8 weeks (group I). Sixteen additional rabbits were operated on using an identical protocol except for the absence of capsular injury (group II). In each group, mechanical testing was performed at the time of Kirschner-wire release in eight animals, and 16 weeks after remobilization in eight animals. At immobilization release, the average contracture was 76 +/- 24 degrees in group I versus 20 +/- 10 degrees in group II (p < 0.001). Sixteen weeks after remobilization, the mean contracture was 49 +/- 15 degrees group I versus 11 +/- 10 degrees in group II (p < 0.001). When associated with bone perforations and immobilization in forced flexion, injury to the posterior capsule results in a severe contracture in the rabbit knee.