Andrew Park

The Inadequacy of Short Knee Radiographs in Evaluating Coronal Alignment After Total Knee Arthroplasty.

BACKGROUND Prior studies have associated coronal alignment after total knee arthroplasty (TKA) with implant survivorship. Results have been based on either the femorotibial angle (FTA) on a short knee film or the hip-knee-ankle angle (HKA) on a full-length radiograph. The purpose of this study was to determine if the FTA on short knee radiographs can accurately predict the true HKA alignment after TKA. METHODS Two orthopedic surgeons measured the FTA, HKA, medial proximal tibial angle, and lateral distal femoral angle in 262 patients who had both short and full-length standing radiographs before and/or after primary TKA. Overall coronal alignment was considered neutral if the FTA was between 2.4° and 7.2° on short knee x-rays or if the HKA was between -3° and 3° on full-length films. RESULTS Preoperatively, 13.9% (26/187) of knees had a neutral FTA on short films, but 50% (13/26) of those were in varus or valgus on full-length films. Postoperatively, 51.4% (106/206) of knees had a neutral FTA on short films, but 27.4% (29/106) of those knees were in varus or valgus on full-length films. When comparing alignment classifications (neutral, varus, or valgus) based on the short vs full-length images, 13.9% (26/187) of patients had discordant classifications on preoperative imaging, and 33.0% (68/206) had discordant classifications on postoperative imaging. CONCLUSION A significant proportion of patients were misclassified as varus, valgus, or neutral based on the FTA when compared to the HKA. Short knee x-rays serve as an inaccurate proxy for full-length films when assessing coronal alignment after TKA.

An update on civilian spinal gunshot wounds: treatment, neurological recovery, and complications

Study Design. Retrospective analysis of inpatient and outpatient data from a single academic trauma center. Objective. To test the effectiveness of a conservative treatment algorithm for civilian spinal gunshot wounds (CSGSWs) by comprehensively evaluating neurological status and recovery, fracture type, concomitant injuries, indications for surgery, and complications. Summary of Background Data. Few large studies exist to guide treatment of CSGSWs, and none have been published in nearly 20 years. Methods. A search of International Classification of Diseases, Ninth Revision (ICD-9) codes was performed for all hospital patients treated from 2003 to 2011 by either neurosurgery or orthopedic surgery to identify 159 consecutive patients who sustained CSGSWs. Mean follow-up was 13.6 months. American Spinal Injury Association grading was used to assess neurological injury. Results. Fifty percent of patients had neurological deficits from CSGSW. Complete spinal injury was the most common injury grade; thoracic injuries had the most risk of complete injury (P < 0.001). Nearly 80% of patients had concomitant injuries to other organs. Operative treatment was more likely in patients with severe neurological injuries (P = 0.008) but was not associated with improved neurological outcomes (P = 1.00). Nonoperative treatment did not lead to any cases of late spinal instability or neurological deterioration. Overall, 31% of patients had an improvement of at least 1 American Spinal Injury Association grade by final follow-up. Nearly half of patients experienced at least 1 GSW-related complication; risk of complications was associated with neurological injury grade (P < 0.001) and operative treatment (P = 0.04). Conclusion. The vast majority of CSGSWs should be managed nonoperatively, regardless of neurological grade or number of spinal columns injured. Indications for surgery include spinal infection and persistent cerebrospinal fluid leaks. Level of Evidence: 3

Inter-Observer Precision and Physiologic Variability of MRI Landmarks Used to Determine Rotational Alignment in Conventional and Patient-Specific TKA

Preoperative planning for patient-specific guides (PSGs) in total knee arthroplasty (TKA) requires identification of anatomic landmarks on three-dimensional imaging studies. The aim of this study was to assess the accuracy and precision with which landmarks commonly used to determine rotational alignment in TKA can be identified on magnetic resonance imaging (MRI). Two orthopedic surgeons and two musculoskeletal radiologists independently reviewed a sequential series of 114 MRIs of arthritic knees. The magnitude of interobserver variability was high, suggesting an inherent risk of inconsistency when these landmarks are used in PSG fabrication. Additionally, there was a high degree of physiologic variation among patients, indicating that assuming standard relationships among anatomic landmarks when placing TKA components may lead to rotational malalignment relative to each patients native anatomy.

Eosinophilic granuloma of the sacrum treated with radiation therapy: a case report.

BACKGROUND CONTEXT Eosinophilic granulomas (EGs) of the sacrum have been reported in fewer than 10 patients. Treatment algorithms for these tumors remain poorly defined; there are no reports of treating solitary sacral EG with radiation therapy (RT). PURPOSE This study aimed to describe the presentation, treatment, and outcome of sacral EG in an adult patient with intractable pain and radiculopathy, treated in a novel fashion with RT. STUDY DESIGN/SETTING The study design was a case report from a tertiary cancer referral center. METHODS Patient records, imaging, and pathology were reviewed. RESULTS A 35-year-old man received 20 Gy of radiation to his S1 EG lesion. He subsequently developed vertebra plana of S1 causing symptomatic L5-S1 stenosis, but 15 months after RT treatment was free of pain or tumor recurrence. CONCLUSION Radiation therapy is an effective treatment option for sacral EG causing severe axial pain and neural impingement.

Malignant Transformation of a Giant Cell Tumor of Bone Treated with Denosumab

Case: Giant cell tumor (GCT) of bone was first described almost 200 years ago, but the optimal treatment continues to evolve. We present a patient with a pelvic GCT who was treated with embolization, 20 months of denosumab therapy, and resection. Histologically, the tumor consisted of degenerated GCT, bone, and fibrous tissue. After 7 months, the patient was found to have osteosarcoma at the site of the initial lesion as well as pulmonary metastases. Conclusion: The apparent malignant transformation of a GCT of bone treated initially with denosumab indicates that close follow-up is warranted.

Percutaneous Discal Cyst Rupture in a Professional Football Player Using Sublaminar Epidural Injection for Thecal Sac Displacement

A case of percutaneous discal cyst rupture in a 25-year-old professional American football player is reported. The patient presented with a 3-day history of severe left-sided back pain. Magnetic resonance imaging examination demonstrated a discal cyst effacing the left L4-L5 lateral recess, with interposed thecal sac. A sublaminar epidural injection was performed displacing the thecal sac, exposing the discal cyst, and allowing for percutaneous perforation. The patient had complete resolution of symptoms after discal cyst rupture and was able to compete in a professional football game 3 days later. Computed tomography-guided percutaneous rupture is a therapeutic modality that may be considered for treatment of a symptomatic discal cyst.