Computerized surgical navigation resection of pelvic region simulated bone tumors using skin fiducial marker registration: an in vitro cadaveric study.

INTRODUCTION: Computerized surgical navigation system guidance can improve bone tumor surgical resection accuracy. This study compared the 10-mm planned resection margin agreement between simulated pelvic-region bone tumors (SPBT) resected using either skin fiducial markers or Kirschner (K)-wires inserted directly into osseous landmarks with navigational system registration under direct observation. We hypothesized that skin fiducial markers would display similar resection margin accuracy. METHODS: Six cadaveric pelvises had one SPBT implanted into each supra-acetabular region. At the left hemi-pelvis, the skin fiducial marker group had guidance from markers placed over the pubic tubercle, the anterior superior iliac spine, the central and more posterior iliac crest, and the greater trochanter (5 markers). At the right hemi-pelvis, the K-wire group had guidance from 1.4-mm-diameter wires inserted into the pubic tubercle, and 3 inserted along the iliac crest (4 K-wires). The senior author, a fellowship-trained surgeon performed "en bloc" SPBT resections. The primary investigator, blinded to group assignment, measured actual resection margins. RESULTS: Twenty of 22 resection margins (91%) in the skin fiducial marker group were within the Bland-Altman plot 95% confidence interval for actual-planned margin mean difference (mean = -0.23 mm; 95% confidence intervals = 2.8 mm, - 3.3 mm). Twenty-one of 22 resection margins (95%) in the K-wire group were within the 95% confidence interval of actual-planned margin mean difference (mean = 0.26 mm; 95% confidence intervals = 1.7 mm, - 1.1 mm). CONCLUSION: Pelvic bone tumor resection with navigational guidance from skin fiducial markers placed over osseous landmarks provided similar accuracy to K-wires inserted into osseous landmarks. Further in vitro studies with different SPBT dimensions/locations and clinical studies will better delineate use efficacy.

Cementless metal-backed patellar components in primary total knee arthroplasty using an implant of modern design.

Aims: The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design. Methods: This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions. Results: A total of 24 TKAs (3.4%) in 24 patients failed and required revision surgery, of which five were due to patellar complications (0.71%): one for aseptic patellar loosening (0.14%) and four for polyethylene dissociation (0.57%). A total of 19 revisions (2.7%) were undertaken in 19 patients for indications which did not relate to the patella: four for aseptic tibial loosening (0.57%), one for aseptic femoral loosening (0.14%), nine for periprosthetic infection (1.3%), one for popliteus impingement (0.14%), and four for instability (0.57%). Knee Society knee and function scores, and ROM, improved significantly when comparing pre- and postoperative values. Survival of the metal-backed patellar component for all-cause failure was 97.5% (95% confidence interval 94.9% to 100%) at 12 years. Conclusion: The second-generation cementless TKA design of metal-backed patellar components showed a 97.5% survival at 12 years, with polyethylene dissociation from the metal-backing being the most common cause of patellar failure. In view of the increased use of TKA, especially in younger, more active, or obese patients, these findings are encouraging at mean follow-up of seven years.

Gender Diversity in Sports Medicine: Current Trends.

As the sports medicine field has grown, the need for a more diverse workforce has become more evident. Given the growing athlete diversity that exists at all recreational and competitive levels of organized sports, it is important to better understand the current state of athletic health care diversity. This review assesses the current state of diversity in sports medicine from the perspective of the medical and athletic training professions. Men and women currently display nearly equivalent participation levels; however, the distribution of female team physicians and athletic trainers could better match the teams that they serve. Although progress has been made, much more needs to be done to bring more female athletic trainers and team physicians into athletic health care leadership roles. Early mentoring programs have shown efficacy for increasing the number of female candidates who might become the foundation of future athletic health care and academic program leaders. Level of Evidence: V, expert opinion.

Use of dual mobility cups in patients undergoing primary total hip arthroplasty with prior lumbar spine fusion.

BACKGROUND: Patients undergoing primary total hip arthroplasty (THA) with prior lumbar spine fusion (LSF) are a high-risk group for instability with reported incidence of dislocation as high as 8.3% using fixed bearing femoral heads. Purpose of this study was to determine risk of post-operative instability in patients undergoing primary THA with a history of prior LSF using dual mobility acetabular cups. METHODS: This was a multicenter retrospective study with 93 patients undergoing primary THA using a dual mobility cup with a prior history of instrumented LSF. There were 56 females and 47 males with an average age of 66 years (46-87) and average BMI of 30 with mean follow-up of 2.7 years (range 12-124 months). Surgical approach included posterior (63), direct lateral (15), anterior (11), and direct superior (4). Forty-four percent had one level lumbar fusion, 29% with two levels, and 15% with three or more levels fused. The primary outcome investigated was instability. RESULTS: There were no cases of instability or prosthetic joint infection in this group of patients with prior lumbar spine fusion undergoing primary THA using a dual mobility cup. There was one intra-operative periprosthetic femur fracture and one case of aseptic acetabular cup loosening. CONCLUSION: Patients undergoing THA with prior LSF are at increased risk for instability due to loss of normal spinopelvic relationship. The use of dual mobility cups in patients with prior LSF undergoing primary THA appears promising with no cases of instability in this high-risk group of patients.

Quadriceps tendon autograft ACL reconstruction has less pivot shift laxity and lower failure rates than hamstring tendon autografts.

PURPOSE: Quadriceps tendon (QT) autograft ACL reconstruction was hypothesized to possess less anterior knee laxity, pivot shift laxity, and lower failure rates than hamstring tendon (HT) autografts. METHODS: Terms "hamstring tendon autograft" and "ACL reconstruction" or "quadriceps tendon autograft" and "ACL reconstruction" were searched in Embase and PubMed. Inclusion criteria required that studies included patients treated for primary ACL injury with reconstruction using either a QT autograft (Group 1) or a HT autograft (Group 2) and instrumented anterior knee laxity assessment. Extracted information included surgical fixation method, graft type, graft thickness or diameter, single vs. double bundle surgical method, publication year, time between the index knee injury and surgery, % women, initial and final subject number, subject age, follow-up length, side-to-side anterior knee laxity difference, Lysholm Score, Subjective IKDC score, anterior knee laxity side-to-side difference grade, ipsilateral pivot shift laxity grade, and failure rate. The Methodological Index for Nonrandomized Studies was used to evaluate study methodological quality. RESULTS: The QT group (Group 1) had 17 studies and the HT group (Group 2) had 61 studies. Overall, Group 2 had greater pivot shift laxity (OR 1.29, 95% CI 1.05-1.59, p = 0.005). Group 2 suspensory femoral fixation had greater pivot shift laxity (OR 1.26, 95% CI 1.01-1.58, p = 0.02) than Group 1 compression femoral fixation. Group 2 compression femoral fixation also had more anterior knee laxity (OR 1.25, 95% CI 1.03-1.52, p = 0.01) than Group 1 compression femoral fixation and higher failure rates based on initial (OR 1.69, 95% CI 1.18-2.4, p = 0.002) and final (OR 1.89, 95% CI 1.32-2.71, p = 0.0003) subject number. Failure rate for HT compression femoral fixation was greater than suspensory femoral fixation based on initial (OR 2.08, 95% CI 1.52-2.84, p < 0.0001) and final (OR 2.26, 95% CI 1.63-3.16, p < 0.0001) subject number. CONCLUSIONS: Overall, QT autografts had less pivot shift laxity and lower failure rates based on final subject number than HT autografts. Compression QT autograft femoral fixation had lower pivot shift laxity than suspensory HT autograft femoral fixation. Compression QT autograft femoral fixation had less anterior knee laxity and lower failure rates than compression HT autograft femoral fixation. Suspensory HT autograft femoral fixation had lower failure rates than compression HT autograft femoral fixation. Greater knee laxity and failure rates may be related to a combination of HT autograft diameter and configuration (tissue quality and dimensions, strands, bundles, and suturing method) variability and fixation mode. LEVEL OF EVIDENCE: Level IV.

Can Revision TKA Patients Achieve Similar Clinical Functional Improvement Compared to Primaries?

The etiology of failure following primary total knee arthroplasty (TKA) leading to revision surgery are multifactorial, including infection, instability, loosening, contracture, and wear. Although the majority of patients have successful outcomes following revision TKA, postoperative complications are still increased in these patients when compared to primary patients. For this reason, there has been a continued search to identify options, including prosthesis types, to potentially improve outcomes. Therefore, the purpose of this study was to determine if the clinical results achieved following revision TKA are comparatively similar to primaries using the same implant design. Specifically, we compared (1) Knee Society Functional and Range-of-Motion Knee Scores and (2) component survivorship. This was a retrospective analysis of 100 patients undergoing revision TKA due to an aseptic etiology, who were matched to a cohort of 100 patients who underwent primaries with the same prosthesis. There were no differences in the groups with respect to age at surgery, sex, and body mass index. The mean follow-up was 57 months in the revision group (range 24-105 months) and 67 months in the primary TKA group (range 55-123 months). American Knee Society Scores (KSS) and range of motion measurements recorded preoperatively and at the most recent postoperative visit were compared between both cohorts in order to compare postoperative outcomes. A p value of 0.05 was used for significance. The average improvement between the pre- and postoperative KSS function scores in both groups was similar, with both cohorts demonstrating a 28-point improvement. At 2-year follow-up, all-cause survivorship of the aseptic revision surgeries was 87%. Patients undergoing revision TKA for aseptic loosening can potentially expect similar improvements in clinical function scores and survivorship compared to primary TKA when controlling for implant type.

Cruciate ligament healing and injury prevention in the age of regenerative medicine and technostress: homeostasis revisited.

PURPOSE: This clinical concepts paper discusses the essential elements of cruciate ligament recuperation, micro-trauma repair, and remodeling. METHODS: Cruciate ligament mechanobiology and tissue heterogeneity, anatomy and vascularity, and synovial membrane and fluid functions are discussed in relationship to deficiency-induced inflammatory responses, nervous and immune system function, recuperation, repair and remodeling, and modern threats to homeostasis. RESULTS: Cruciate ligament surgical procedures do not appreciate the vital linked functions of the central, peripheral, and autonomic nervous systems and immune system function on knee ligament injury recuperation, micro-trauma repair, and remodeling. Enhanced knowledge of these systems could provide innovative ways to decrease primary non-contact knee injury rates and improve outcomes following reconstruction or primary repair. CONCLUSIONS: Restoration of knee joint homeostasis is essential to cruciate ligament recuperation, micro-trauma repair, and remodeling. The nervous and immune systems are intricately involved in this process. Varying combinations of high-intensity training, under-recovery, technostress, and environmental pollutants (including noise) regularly expose many athletically active individuals to factors that abrogate the environment needed for cruciate ligament recuperation, micro-trauma repair, and remodeling. Current sports training practice, lifestyle psychobehaviors, and environmental factors combine to increase both primary non-contact knee injury risk and the nervous and immune system dysregulation that lead to poor sleep, increased anxiety, and poorly regulated hormone and cytokine levels. These factors may create a worst-case scenario leading to poor ligament recuperation, micro-trauma repair, and remodeling. Early recognition and modification of these factors may decrease knee ligament injury rates and improve cruciate ligament repair or reconstruction outcomes. LEVEL OF EVIDENCE: V.