John S. Kirkpatrick

Manifestations of the Battered-child Syndrome

Between 1965 and 1972, 231 patients were admitted to St. Christophers Hospital for Children in Philadelphia with the battered-child syndrome. The case records and reontgenograms of 217 patients were reviewed. About one-third of the patients repuired orthopaedic treatment. The purpose of this paper is to alert the orthopaedist to the existence and prevalence of the battered-child syndrome, to describe both the non-orthopaedic and the orthopaedic manifestations of this problem, and to delineate the orthopaedists responsibility to the battered child and the childs family.

Short Segment Fixation of Thoracolumbar Burst Fractures

Short segment instrumentation for thoracolumbar fractures or fracture dislocations continues to be controversial. Recently, a load-sharing classification score was developed to help predict failure of posterior instrumented fusion alone used for highly comminuted and kyphotic fractures. Twenty-two patients treated with short-segment posterior instrumentation for thoracolumbar fractures were retrospectively reviewed. Although posterior instrumented fusion was used for fractures with a relatively high load sharing classification score, the load-sharing classification score was not predictive of posterior instrumentation failure. Single-level cephalad instrumentation failed at a higher rate than two-level cephalad instrumentation.

Thoracolumbar fracture management: anterior approach.

Abstract The surgeon who treats patients with spine trauma must be able to apply a variety of management techniques to achieve optimal care of the patient. The anterior surgical approach is appropriate for some thoracolumbar burst fractures in patients with neurologic deficit and without posterior ligamentous injury. Surgery is most often indicated for patients with incomplete deficit, especially those with a large retropulsed fragment, marked canal compromise, severe anterior comminution, or kyphosis >30°. This approach provides excellent visualization of the anterior aspect of the dura mater for decompression. Reconstruction of the anterior body defect can be done with autograft, allograft, or a cage. Supplementation of the graft with anterior internal fixation helps prevent kyphosis. Clinical results demonstrate improved neurologic function in most patients as well as low pseudarthrosis rates. In patients with incomplete deficit, improvement in neurologic function usually can be expected with few complications.

The acute effects of posterior fusion instrumentation on kinematics and intradiscal pressure of the human lumbar spine

Nine cadaver lumbar spines were analyzed by applying nonconstraining nondestructive bending moments while measuring global range of motion, mechanical reaction at the sacrum, applied moment at the top of the specimen, segmental range of motion at L1–L5, and IDP at L1–L4. Each specimen was examined in an intact and instrumented state (with L3–L4 posterior instrumentation) using range of motion-based biomechanical testing, while achieving a similar global ROM in the sagittal, frontal, and transverse planes. An increase in applied moment was required during instrumented testing when compared with intact, and a significant increase in segmental range of motion during instrumented testing was found at all uninstrumented levels. Significant decreases in segmental range of motion were measured at the instrumented level when compared with intact testing. The most significant decreases and increases in IDP occurred at the instrumented level during sagittal and transverse plane testing.

The FDA Process for the Evaluation and Approval of Orthopaedic Devices

Abstract The US Food and Drug Administration (FDA) is a scientific, regulatory, and public health agency whose authority includes overseeing the marketing of products relevant to medical practice. Devices are classified based on the extent of oversight needed to ensure public safety. Divisions within the FDA provide specific expertise regarding drugs, devices, biologic products, and combinations thereof. Various pathways exist to apply for marketing through the FDA, depending on the nature of the product and its intended use. Expert panels advise the agency on issues related to product safety and efficacy, and clinical studies may be required to provide data based on these parameters. Clinical data are monitored postapproval for potential adverse events not evident in earlier trials. Orthopaedic surgeons are involved in all aspects of the FDA as employees, consultants, product advocates, participants in clinical trials and advisory panels, and experts involved in the appropriate reporting of adverse events.

A comparison C1-C2 transarticular screw placement after self-education and mentored education of orthopaedic residents.

Study Design: Prospective randomized trial. Objective: This study will provide preliminary data on whether residents can be “self‐taught” and to what extent a lecture, demonstration, and coaching can improve skills and knowledge. Background Data: Practice‐based learning is an essential competency in Accreditation Council for graduate Medical Education‐accredited residencies. Little has been done to demonstrate whether residents can be self‐taught or benefit from mentoring in understanding and performing difficult surgical tasks. Methods: A written test was given to orthopedic residents on C1–C2 transarticular screw placement. They were then provided reading on C1–C2 transarticular screw placement. Residents were then divided into a “self‐directed learning” group and a “mentored learning” group. All residents then performed the technique on models, with the “mentored” group receiving a lecture and coaching from the mentor. The models were analyzed for technique errors and the previous test was administered again as a posttest. The test and screw placement were repeated 4 months later. Results: Residents without mentoring had an average improvement of 4.5 points, those with mentoring had average improvement of 8.6 points (P=0.0068). The screw placement technique error rate for the nonmentored group (n=8) was 2.55, and for the mentored group (n=9) was 1.47 (P=0.004). Sixteen residents completed the delayed test, 7 from the nonmentored groups and 8 from the mentored group. Nine residents were able to repeat the screw placement technique 4 months after the initial test and screw placement, 3 nonentored, and 6 mentored. Although there were some trends toward the mentored group having better retention, neither knowledge nor skill was statistically different. Conclusions: This preliminary trial seems to indicate that residents provided a lecture and guided technical instruction will obtain knowledge and perform procedures better than those that do not. Conclusions based upon Post Graduate year, motivation, and interest in spine surgery could not be made.

Reporting and notification of adverse events in orthopaedics.

Surgeons should know how to alert the US FDA when an adverse event occurs with a device that has been approved by the FDA. Documentation of such events is critically important to help identify trends concerning a particular device, thereby helping surgeons and other health care professionals avoid similar events. The FDA created the MedWatch program to aid health care professionals in reporting adverse events. Orthopaedic surgeons can use the program to get up-to-date alerts and help protect their patients.

The ability of MRI to predict failure of nonoperative treatment of pyogenic vertebral osteomyelitis.

Pyogenic vertebral osteomyelitis (PVO) can be treated most often by medical management. For those failing with medical management, surgical delay can result in increased morbidity. Therefore, the ability to predict failure of medical management on presentation would greatly improve the outcome. This study determines the ability of the presenting magnetic resonance imaging scan to predict failure of nonoperative management at the onset of treatment. A cohort of patients with PVO, initially treated medically, was reviewed. Imaging, demographics, and clinical data of patients successfully treated medically were compared with those ultimately requiring surgical treatment. The extent of signal change on the T1-weighted sagittal images of the affected motion segment was determined for each group. Twenty-two patients were included in the study. Patients successfully treated medically averaged 57%±19% of motion segment involvement, whereas those failing conservative treatment averaged 89%±18%. Using 90% involvement as an indication for initial surgery would have a sensitivity of 78% and specificity of 93%. Patients with thoracolumbar PVO who have 90% or higher involvement of an affected motion segment should be considered for early operative management.

Measurement of a posterior occipitocervical fusion angle.

Study Design A method for evaluating occipitocervical neutral position is described. Objective To describe and measure a posterior occipitocervical angle (POCA) in normal subjects that can be used to guide contouring of fusion implants to achieve occipitocervical neutral fusion and for use in standardized testing of occipitocervical constructs. Summary of Background Data The goal of occipitocervical fusion is to fuse the head in an ideal functional position. Several methods of estimating occipitocervical neutral position have been described and tested, yet none has been proven superior. An ideal method would easily and reproducibly aid in evaluating occipitocervical position intraoperatively and potentially aid in the design and testing of implant constructs. Methods Fifteen adult lateral cervical spine radiographs taken in occipitocervical neutral position and interpreted as normal by an experienced radiologist were studied. Analysis consisted of measurement of the POCA. The POCA is defined as the angle formed by the intersection of a line drawn tangential to the posterior aspect of the occipital protuberance and a line determined by the posterior aspect of the facets of the third and fourth cervical vertebrae. Results The mean POCA was 109.7 degrees with a SD of 5.7 degrees. Compilation of the data revealed a normal distribution of measurements where 80% of the POCA values were between 101 and 119 degrees. Conclusions POCA is a simple measurement that may be valuable as an intraoperative tool during occipitocervical fusion and may aid the design and testing of fusion implants and their application in the operating room.

Micropuncture needles combined with ultrasound guidance for unusual central venous cannulation: desperate times call for desperate measures--a new trick for old anesthesiologists.

Central vascular access can be a very challenging task in patients with skeletal deformities such as ankylosing spondylitis, kyphosis, and chin-on-chest deformity. The use of traditional methods of accessing the central venous circulation in these patients can require multiple attempts and may lead to significant complications such as bleeding, pneumothorax, and vascular injury. Ultrasound-guided central venous access has become a very common procedure in the United States and Europe; its efficacy and safety have been demonstrated, and together with the use of micropuncture needles, the technique can facilitate central venous access in complicated cases.