Faculty Bibliography

BACKGROUND CONTEXT: The relationship between pelvic incidence (PI) and lumbar lordosis (LL) has been well established as a key determinant of sagittal alignment and satisfactory surgical outcomes. The goal of matching PI and LL within 10degree works as a general rule, but may not apply to patients with lower or higher PI. PURPOSE: To analyze the relationship between pelvic incidence and lumbar lordosis required for optimal alignment in patients with extreme PI values. STUDY DESIGN/SETTING: Multicenter retrospective study, ASD patients from 2 databases. PATIENT SAMPLE: 88 patients from a PSO database (1-year follow-up), 142 patients from a prospective database (PON) (2 years follow-up). Age >18 years. OUTCOME MEASURES: Radiographic measurements, pelvic incidence and PI-LL METHODS: Subjects with at least 1 year follow-up were identified from a multicenter database of patients who underwent a pedicle subtraction osteotomy (PSO) from 2004-2013. Patients were included if they were well aligned (WA) based on Vialle criteria, with PT<12degreeand T1SPI between -4.05degreeand 1.35degree. The distribution of the PI was analyzed to create the following 3 groups: Low PI (LPI; < Mean - 1 S.D.), Average PI (API; Mean +/- 1 S.D), High PI (HPI; > Mean + 1 S.D.), and an ANOVA test was carried out to compare. The same analysis was performed on a separate group of patients issued from a prospective database with at least a 2-year follow-up (PON) in order to validate these results. RESULTS: The PSO cohort included 88 patients, mean age=56.2 yo. Mean PI was 57.1 +/- 15.2degree. The analysis of the PI-LL for the 3 groups revealed that the HPI required a lordosis smaller than the PI (PILL=17.7 degree), the API required a lordosis similar to the PI (PI-LL=1.75degree), and the LPI required greater LL than the PI (PI-LL=-11.02degree). There were significant differences between the PI-LL parameter of the HPI group (17.69degree) and the two other groups (API group: -1.75degree, and LPI group: -11.02degree, p<.001). The PO!

BACKGROUND CONTEXT: Sagittal spinal deformity (SSD) patients recruit compensatory mechanisms to maintain erect posture and align the head over the pelvis. Spinopelvic mechanisms of compensation involving retroversion of the pelvis have been described. Additionally, knee flexion and pelvic shift have been proposed as limbs mechanisms, but how and when these mechanisms contribute is poorly understood. PURPOSE: To determine the percentage of spinal, pelvic and lower extremity compensatory response based on global spinal deformity. STUDY DESIGN/SETTING: Single-center, retrospective review of fullbody head-to-foot stereoradiographs. PATIENT SAMPLE: 435 patients with spinal sagittal deformity from November 2012 to November 2013. OUTCOME MEASURES: Oswestry Disability Index (ODI), Short Form 36 Health Questionnaire (SF-36; Physical Component Score [PCS] and Mental Component Score [MCS]), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), knee angle (KA) and pelvic shift angle (PSh). METHODS: This is a retrospective review of adult SSD patients who underwent stereoradiography (EOS imaging system) between 2012- 2013. Radiographic measurements were performed with Surgimap (Nemaris Inc.). Patients with a PI greater than LL were categorized based on their mismatch and compared in terms of compensatory mechanisms normalized to each patient's PI-LL: PT, Knee flexion and pelvic shift angle (the angle between the lines formed from the posterior-superior corner of S1 to the anterior distal cortex of the tibia and the vertical). RESULTS: 161 Patients were included with a mean age of 62.93+12.8yrs, BMI 27, and 80.6% females. At baseline, patients had a mean SVA 62.3+61.5mm, PT 29.2+8.4 degree , and PI-LL 21.0+14.9 degree . Patients were categorized based on their PI-LL in 4 groups of PI-LL by mismatch 10 degree (Group 1: PI-LL 0-10 degree , Group 2: 10-20 degree , Group 3: 20-30 degree , and Group 4: >40 degree ). There were significant differences between all groups in PT!

BACKGROUND CONTEXT: Understanding various components of global alignment is essential in the effective treatment of sagittal spinal deformity patients (SSD). Despite the development of EOS and full body radiographic technology, sagittal plane assessment commonly remains limited to the spinopelvic area. Evaluation of lower limb compensatory mechanisms has been poorly understood to date. PURPOSE: The objective of this study was to investigate the role of the lower limbs in maintaining erect posture and horizontal gaze in the setting of SSD. STUDY DESIGN/SETTING: Single-center, retrospective review of fulllength head to foot stereoradiographs. PATIENT SAMPLE: 435 patients with spinal sagittal deformity from November 2012 to November 2013. OUTCOME MEASURES: Oswestry Disability Index (ODI), Short Form 36 Health Questionnaire (SF-36; Physical Component Score [PCS] and Mental Component Score [MCS]), Chin Brow Vertical Angle (CBVA), pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt (PT), sagittal vertical axis (SVA), T1 pelvic angle (TPA), knee angle flexion (KA), ankle angle flexion (AA) and sacral femoral angle (SFA). METHODS: In this retrospective study, patients with spinal pathology underwent low dose stereoradiography X-rays (EOS imaging systemdegree). The inclusion criteria were SSD with a PI-LL mismatch>15degree and functional horizontal gaze (CBVA between -4 and 17degree). Patients were divided in 2 groups based on their PI-LL mismatch after surgery: over corrected (OC, PI-LL<-15degree) and under corrected (UC, PI-LL>15degree). Groups were compared in terms of sagittal alignment and lower limb compensatory mechanisms (Student T test). Correlations and regression were performed to predict lower extremity compensation. RESULTS: Eighty-six patients (mean age 55.5 years, BMI 26.4kg/m2, 75% female) were included: 29 UC and 57 OC. By definition, UC patients had a significantly more sagittal spinopelvic deformity (PI-LL, SVA, and TPA) as well as a larger PI, SFA (hip hyperextension), KA and AA!

Obesity has been shown to be a risk factor for degenerative knee arthritis and its incidence is increasing in epidemic proportions. Obesity has also been shown to be a risk factor for surgical complications associated with total knee replacement (TKR) surgery. There have been no prior investigations examining the relationship between body mass index (BMI) and surgical time during TKR. Two hundred and seventy three patients were evaluated and stratified by BMI. There was a direct linear relationship between BMI and operative time. In addition, the higher the BMI group, the younger the age at surgery, and obese class III patients experienced a higher rate of early post-operative complication. Therefore, patients should be counseled that obesity prior to TKR surgery might lead to a longer operative time and any sequelae associated with further exposure of the operative wound, especially with regard to higher rates of prosthetic joint infection (PJI).

Indications for UKA for isolated osteoarthritis of the knee remain controversial. Two hundred twenty-nine UKA that were performed at our institution were evaluated for which factors were associated with a poor outcome. BMI >35 was correlated with lower KSS scores than patients with BMI <35. In contrast to prior reports, patients younger than 60 years old had higher scores than patients 60 years and older at 2 years. Women had an unacceptably high short-term revision rate for any reason of 6.5%. Popularity for UKA has increased, and a more in depth investigation of predictors of poor outcomes demonstrates that younger patients appear to have better results. Obese patients continue to improve up to 2 years after surgery and should not be precluded from undergoing UKA.

INTRODUCTION/PURPOSE/OBJECTIVE:Cruciate retaining total knee replacement has been shown to effectively improve pain and quality of life. Successful outcomes depend on many factors, including the maintenance of a competent posterior cruciate ligament. This study sought to anatomically analyze the percentage of PCL injured during a full transverse, tibial cut, thus altering normal function. MATERIALS AND METHODS/METHODS:One hundred and thirty five consecutive knee MRIs taken from 2006 to 2011 were selected from a single surgeon's database for this study. Only subjects with non-arthritic knees were considered for this study; the lack of degenerative joint disease (DJD) was confirmed via a radiological report. The optimal view of the PCL's tibial attachment was observed using the sagittal view of the knee, with a T1 signal. One hundred and twenty two usable images were viewed electronically, and measurements were made using the standardized transverse cut implant guidelines. The percentage of PCL remaining following the cut was categorized into five different groups: 0% (no PCL undermined), 1-49%, 50-74%, 75-99% and 100% (PCL undermined entirely). RESULTS:Overall only 9.0% (n=11) would have not endured any damage to the PCL with a transverse tibial saw cut, while 79.6% (n=98) would have had 50% or more of the PCL undermined. Of the 98 patients with more than 50% resected, 52.1% (n=51 patients) presented complete destabilization of the PCL. The percentage of PCL destabilized was not significant across age groups (p=0.280), gender (p=0.586), or operative side (p=0.460). CONCLUSION/CONCLUSIONS:Independent of age, gender, and operative side, a majority of PCLs are more than 50% destabilized following the standard transverse tibial cut. LEVEL OF EVIDENCE/METHODS:II.

The definitive treatment for advanced joint destruction in the late stages of rheumatoid arthritis can be successfully treated with total joint arthroplasty. Total knee arthroplasty has been shown to be a well-proven modality that can provide pain relief and restoration of mobility for those with debilitating knee arthritis. It is important for rheumatologists and orthopedic surgeons alike to share an understanding of the special considerations that must be addressed in this unique population of patients to ensure success in the immediate perioperative and postoperative periods including specific modalities to maximize success.

OBJECTIVE:Serum albumin has long been used in clinical practice as a marker of protein-energy undernutrition, but very few studies have focused on its relation with dual-energy X-ray absorptiometry-assessed lean mass measurements, which is the current reference method in routine for body composition-related nutritional status. Serum albumin concentration is also affected by non-nutrition-related factors, and there is published evidence on the relation between serum albumin concentration and morbidity/mortality in the elderly. This study was designed to examine the relationship between serum albumin and lean mass and nutrition-related risk of morbidity/mortality in geriatric patients. Our objective was to clarify whether serum albumin in geriatric patients is a marker of body composition-related nutritional status, risk of morbidity/mortality, neither, or both. METHODS:This prospective study enrolled 125 elderly patients hospitalized in a rehabilitation unit [83.8 (SD 7.7) y]. Subjects were evaluated for serum albumin concentration and nutritional status at admission [body mass index, lean mass, appendicular skeletal muscle mass index, and body cell mass index (calculated as the ratio of the mass to the square of the height), evaluated by dual-energy X-ray absorptiometry combined with bioelectrical impedance analysis]. Outcome scores were assessed 6 mo later, taking into account complications (pressure ulcers and/or infections) and 6-mo mortality. RESULTS:Serum albumin concentration was not correlated with the lean mass, appendicular skeletal muscle mass, or body cell mass indexes. Serum albumin concentration was, however, correlated with outcome score (r = 0.22, P = 0.02). CONCLUSION/CONCLUSIONS:This study clearly demonstrates that albumin is not suitable as a marker of body composition in elderly patients.