Field Of Orthopaedic Surgery Research Articles

Predictors of nonunion and reoperation in patients with fractures of the tibia: an observational study

BackgroundTibial shaft fractures are the most common long bone fracture and are prone to complications such as nonunion requiring reoperations to promote fracture healing. We aimed to determine the fracture characteristics associated with tibial fracture nonunion, and their predictive value on the need for reoperation. We further aimed to evaluate the predictive value of a previously-developed prognostic index of three fracture characteristics on nonunion and reoperation rate.MethodsWe conducted an observational study and developed a risk factor list from previous literature and key informants in the field of orthopaedic surgery, as well as via a sample-to-redundancy strategy. We evaluated 22 potential risk factors for the development of tibial fracture nonunion in 200 tibial fractures. We also evaluated the predictive value of a previously-identified prognostic risk index on secondary intervention and/or reoperation rate. Two individuals independently extracted the data from 200 patient electronic medical records. An independent reviewer assessed the initial x-ray, the post-operative x-ray, and all available sequential x-rays. Regression and chi-square analysis was used to evaluate potential associations.ResultsIn our cohort of patients, 37 (18.5%) had a nonunion and 27 (13.5%) underwent a reoperation. Patients with a nonunion were 97 times (95% CI 25.8-366.5) more likely to have a reoperation. Multivariable logistic regression revealed that fractures with less than 25% cortical continuity were predictive of nonunion (odds ratio = 4.72; p = 0.02). Such fractures also accounted for all of the reoperations identified in our sample. Furthermore, our data provided preliminary validation of a previous risk index predictive of reoperation that includes the presence of a fracture gap post-fixation, open fracture, and transverse fracture type as variables, with an aggregate of fracture gap and an open fracture yielding patients with the highest risk of developing a nonunion.ConclusionsWe identified a significant association between degree of cortical continuity and the development of a nonunion and risk for reoperation in tibial shaft fractures. In addition, our study supports the predictive value of a previous prognostic index, which inform discussion of prognosis following operative management of tibial fractures.

Author's Reply

First, we feel honored receiving interest by such an authority in the field of orthopedic knee surgery as Dr. Merchant. However, we disagree with his statement that the turn-up sign to 90° was quickly discarded or never adopted after being described in 1986.1Henry J.H. Goletz T.H. Williamson B. Lateral retinacular release in patellofemoral subluxation. Indications, results, and comparison to open patellofemoral reconstruction.Am J Sports Med. 1986; 14: 121-129Crossref PubMed Scopus (70) Google Scholar No evidence or recommendation was available in the listed international publications when we started our prospective study in 2008. In contrast, the current “state-of-the-art” technique in 2008 as described in Master Techniques in Orthopaedic Surgery: Reconstructive Knee Surgery pointed out that “a turn-up sign of 90° should be performed to assure adequate release” (Figure 1.9, page 9).2Gasser S. Cucchetti B. Arthroscopic lateral release of the patella with radiofrequency ablation.in: Jackson D. Master techniques in orthopaedic surgery: Reconstructive knee surgery. Ed 3. Lippincott, Williams & Wilkins, Philadelphia2008: 1-11Google Scholar The authors of this book and article are renowned chairmen and experts in the field of orthopaedic surgery in the United States, but obviously have not been aware of the potential risk of the 90° turn-up sign during release. In contrast, Dr. Merchant mentioned the book chapter published by Ewing3Ewing J.W. Arthroscopic patellar shaving and lateral retinacular release.in: McGinty J.B. Operative arthroscopy. Raven, New York1991Google Scholar in 1991 that recommended a turn-up of 60°. Unfortunately, this book chapter is not available in the listed scientific material for international specialists. In addition, we could not find Dr. Merchant's personal publication in the available literature that gives the recommendation to limit the turn-up sign to less than 90°. We immediately published our results and our recommendation to reduce the turn-up sign to 70° (included in the “Discussion” section of our article).4Pagenstert G. Wolf N. Bachmann M. et al.Open lateral patellar retinacular lengthening versus open retinacular release in lateral patellar hypercompression syndrome: A prospective double-blinded comparative study on complications and outcome.Arthroscopy. 2012; 28: 788-797Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar We absolutely agree that the publication of Dr. Merchant's letter together with our study will help to correct this deficiency of knowledge in US and international orthopaedic societies. Finally, we really appreciate this kind of discussion based on letters to the editor, because it points out minor details that turn out to be most critical in obtaining good or bad results. However, we will not repeat the study with a turn-up sign of 60° or 70° because we believe, in our Level II evidence, that lateral retinacular lengthening will give better results than simply cutting the lateral retinaculum because of preserved muscle, iliotibial band, and retinacular fiber connection despite the extent of the turn-up sign used. We hope other readers will take the opportunity to share in our discussion and follow our consensus recommendation for a limited turn-up sign during lateral retinacular release. Is It Lateral Retinacular Lengthening Versus Lateral Retinacular Release or Over-Release?ArthroscopyVol. 29Issue 3PreviewAs the first author to publish about the lateral release, in 1974,1 I feel an obligation to comment on the article “Open Lateral Patellar Retinacular Lengthening Versus Open Retinacular Release in Lateral Patellar Hypercompression Syndrome: A Prospective Double-Blinded Comparative Study on Complications and Outcome” by Pagenstert et al.2 in the June 2012 issue of Arthroscopy. The abstract describes a well-designed prospective study with the results clearly favoring lengthening compared with release. Full-Text PDF

Wartime orthopaedic residency

Abstract : The terrorist attacks of September 11, 2001, and the ensuing war on terror including major conflicts in Iraq and Afghanistan have lead to changes in many aspects of the world. This is true even in medical education, and the experiences of current residents and recent graduates have been affected in many ways, developing the field of orthopaedic surgery and its practitioners in areas of technical innovation, military experience, personal maturity and a sense of duty while providing opportunities for mentorship and interservice collaboration. The authors present their unique experiences as a prior Marine Corps Officer and General Medical Officer and the benefits of orthopaedic residency training in military training facilities during a time of conflict.

Surface properties of polyurethane composites for biomedical applications

The development of tissue engineering in the field of orthopedic surgery is now booming. Biocompatibility is one of the most important characteristics of a biomedical polymer and composites material whose surface is required to interact with a biological system. Since proteins are viewed as the primary and the most important substrate in mediating polymer–organism interactions, the status of the proteins on a material surface is believed to determine the ultimate biocompatibility of a given biomaterial. In order to achieve specific responses between biomaterial surfaces and the adjacent cells, the principles for designing biocompatible materials are brought forth decorating polymer surfaces with bioceramic particles (aragonite and calcite) to induce specific protein adsorption and cell responses. In this work, we describe the adhesion properties of polyurethane/calcium carbonate composites. An understanding of the phenomena of cell adhesion and, in particular, understanding of the proteins involved in osteoblast adhesion on contact with the materials is of crucial importance, the adhesion between fibronectin (FN) and composites PUR/CaCO3 surfaces were examined using atomic force microscopy (AFM). Moreover, it is found that is correlation between the detachment force and surface free energy (SFE). At the end, in order to estimate the cellular biocompatibility, the human bone derived cells (HBDC) were cultured on PUR/CaCO3 composites.

Controlled release of gentamicin from gelatin/genipin reinforced beta-tricalcium phosphate scaffold for the treatment of osteomyelitis.

Infection of the bone (osteomyelitis) remains one of the most challenging problems in the field of orthopedic surgery. The limitations of systemic antibiotics administration include undesired side effects, systemic toxicity, patient discomfort, and development of bacterial resistance. In this study, we developed a bactericidal gentamicin-doped beta-tricalcium phosphate (TCP) scaffold reinforced with a gelatin/genipin hydrogel (G-TCP). Our data showed that the gentamicin-doped G-TCP had a much longer drug releasing period, while the gentamicin was completely released from pure TCP cements (B-TCP) within one day. In addition, the release profile of G-TCP exhibited an initial burst followed by a zero-order release. One standard strain, Staphylococcus aureus (S. aureus, ATCC25923) was selected to evaluate the antibacterial activity and therapeutic effect of this scaffold. G-TCP significantly inhibited growth of S. aureus both in vitro and in vivo. In a rat osteomyelitis model, osteomyelitis could be totally cured after implantation of G-TCP for three weeks. We propose that the gelatin/genipin-gentamicin TCP scaffold represents one of the promising gentamicin releasing bone scaffolds in treating osteomyelitis.

Wissens‐Hunger im Stall: Die Entstehung von Knochen‐Schafen als Versuchstiere in der Unfallchirurgie

AbstractEpistemic‐Hunger in the Stable: The Genesis of Bone‐Sheep as Experimental Animals in Orthopedic Surgery. The text explores the coming‐into‐being of bone‐sheep as experimental animals in the field of orthopedic surgery from the 1960s onwards. Sheep replaced dogs – mainly for emotional reasons – as test subjects for newly developed implants like plates and screws, which were used for fracture care in humans and in pet animals. Utilizing a praxeographic approach in the framework of material semiotics, the history of bone‐sheep is examined more closely in order to explore how different sheep ontologies (e.g. bone‐sheep and meat‐sheep) are intertwined. Ontologies are understood as specific modes of existence: a set of simultaneous multiple realities which are coproduced by animals and humans and which do not align into a single coherent reality. Materiality is not understood as pre‐given but rather as an effect of practices of relating, connecting and cutting – thus producing – heterogeneities like bone‐sheep. Those practices can be understood as a form of ’ontological politics', which describes the interactions between different ontological realities. By paying specific attention to the phenomenon of hunger and practices of feeding, the text examines the ontological politics of synchronization between the epistemic hunger – the data‐collection or scientific hunger of the researchers – and the ontological hunger of the sheep themselves, which can be seen as crucial in the materialization of bone‐sheep.

Evaluation, Characterization and Cell Viability of Ceramic Scaffold and Nano-gold loaded Ceramic Scaffold for Bone Tissue Engineering

Orthopaedic implants and metal implantation are major technological contributions in the field of orthopaedic surgery. However, bacterial infection and inflammation are predicament issues that subsequently lead to implant failure and second surgery. Ceramic scaffold loaded with gold nanoparticles (Au NPs) posse's antimicrobial and anti-inflammatory properties, which would be more ideal for successful bone implantation and tissue regeneration. Thereby, Hydroxyapatite nanoparticles (nHA), β-Tricalcium Phosphate nanoparticles (nβ-TCP), and Au NPs were used for the fabrication of ceramic scaffold and Au NPs loaded ceramic scaffold. The effects of the Au NPs on the scaffold's mechanical properties, porosity and cell growth have been evaluated. Scanning Electron Microscope [1] and test metric universal testing machine were employed for characterization of the scaffolds. Gold loaded scaffold demonstrated enhanced porosity, degradability and mechanical properties compared with the ceramic scaffold. The porosity of the ceramic and Au NPs loaded ceramic scaffold ranged between 30-50% and 60-75%, respectively, while compressive strength ranged between 10-30mPa and 25-45mPa, respectively.. Scaffold synthesis can be used for implantation in organs that need high load bearing such as femurs, tibia and also as a substrate for Au NPs delivery. To our knowledge, Au NPs have not been incorporate previously with calcium phosphate for fabrication scaffold for bone grafting. Also this study the first report on the effects of Au NPS on the mechanical properties, porosity and degradation rates of ceramic scaffolds.

Poster 67: Using Raman Spectroscopy To Evaluate Bone Graft and Implant Osseointegration Non-Invasively: A Novel and Groundbreaking Technique

Evaluating bone grafts, in particular the bone growth process, can be an arduous, time consuming process. The standard method is utilizing radiographs and clinical evaluation. These methods, while effective and widely accepted, do not give information regarding the metabolic activity of the bone being analyzed. Recently, a new and innovative method utilizing principles found in modern physics has been studied in the field of orthopedic surgery. This method, called Raman Spectroscopy, is being extensively studied as a means to evaluate bone grafts in the femur of rat subjects, with the hope of being used on human subjects.

Challenges and Opportunities in Developing Quality Initiatives in Orthopaedics

With a renewed focus on quality in US health care, the field of orthopaedic surgery faces both challenges and opportunities to lead the way in providing high-quality musculoskeletal care for patients. Orthopaedics has historically been an eminence-based and tradition-based specialty, and the future will require more evidence in the form of higher-level clinical studies. The orthopaedic oncology literature in 1 leading journal is analyzed between 2005 and 2011 to highlight the published levels of evidence. Models of quality initiatives from leading medical specialty organizations such as the American College of Cardiology are provided. A brief history of past quality efforts from the American Academy of Orthopaedic Surgeons as well as a more detailed review of the current initiatives including clinical practice guidelines, technology overviews, and appropriate use criteria are listed.

Variability in the Definition and Perceived Causes of Delayed Unions and Nonunions

Despite the large number of fracture outcome studies, there remains variability in the definitions of fracture-healing. It is unclear how orthopaedic surgeons are diagnosing and managing delayed unions and nonunions in clinical practice. We aimed to explore the current opinions of orthopaedic surgeons with regard to defining, diagnosing, and treating delayed unions and nonunions in extremity fractures. We developed a survey using previous literature, key informants in the field of orthopaedic surgery, and a sample-to-redundancy strategy. Our final survey contained four sections and twenty-nine questions focusing on demographics and surgical experience, definitions of fracture union, prognostic factors for union, and the need for clinical trials. The Internet-based survey and follow-up e-mails were continued until our a priori sample size of a minimum of 320 completed and eligible responses were collected. Three hundred and thirty-five surgeons completed the survey. The typical respondent was a North American, male orthopaedic surgeon or consultant over the age of thirty years who had completed trauma fellowship training, worked in an academic practice, supervised residents, and had more than six years of experience in treating orthopaedic injuries. Most surgeons endorsed a lack of standardization in definitions for delayed unions (73%) and nonunions (55%); almost all agreed that defining a delayed union and nonunion should be done on the basis of both radiographic and clinical criteria (88%). Most respondents believed that the degree of soft-tissue injury (approximately 93%), smoking history (approximately 82%), and vascular disease (approximately 76%) increased the risk of healing complications. Surgeons use similar prognostic factors to define and assess delayed unions and nonunions, but there is a lack of consensus in the definitions of delayed union and nonunion. The need for standardization and future randomized trials was strongly endorsed.

Complications of arthroscopic surgery of the hip.

Over recent years hip arthroscopic surgery has evolved into one of the most rapidly expanding fields in orthopaedic surgery. Complications are largely transient and incidences between 0.5% and 6.4% have been reported. However, major complications can and do occur. This article analyses the reported complications and makes recommendations based on the literature review and personal experience on how to minimise them.

The “Cello Technique”: A New Technique for Ultrasound-Assisted Calcaneoplasty

The “cello technique” is a new calcaneoplasty technique for the treatment of Haglund disease. It is an ultrasound-assisted technique for resection of the posterosuperior part of the calcaneus. It is possible to resect the posterosuperior part of the calcaneus under direct ultrasound control with the patient in the prone position, with a dorsally positioned ultrasound probe, in line with the Achilles tendon fibers (sagittal line), and with the abrader in the posteromedial working portal. We describe in detail the technique for this new procedure in foot and ankle surgery. This innovative technique offers the possibility of expanding the indications for ultrasound-guided surgery in other fields of orthopaedic surgery.

Properties of Cartilage Engineered from Elderly Human Chondrocytes for Articular Surface Repair

Numerous studies on engineering cartilage utilizing chondrocytes from juvenile animal sources have been reported. However, there are many unknown aspects of engineering cartilage using human chondrocytes-especially from middle-aged or elderly adults-which are critical for clinical application of tissue engineering in the field of orthopedic surgery. The primary aim of this study was to engineer neocartilage tissue from 50-60-year-old human chondrocytes in comparison to engineered cartilage made from juvenile swine chondrocytes (JSCs). Articular chondrocytes from middle-aged, nonarthritic humans and juvenile swine were isolated and placed in culture for expansion. The chondrocytes (passage 1) were mixed in fibrin gel at 40-60×10(6) cells/mL until polymerization. Cells/nodule constructs and devitalized cartilage-cells/hydrogel-devitalized cartilage constructs (three-layered model) were implanted into subcutaneous pockets of nude mice for 12, 18, and 24 weeks. The specimens were evaluated histologically, biochemically, and biomechanically. This allowed for direct comparison of the cartilage engineered from human versus swine cells. Histological analysis demonstrated that samples engineered utilizing chondrocytes from middle-aged adults accumulated basophilic, sulfated glycosaminoglycans (sGAG), and abundant type II collagen around the cells in a manner similar to that seen in samples engineered using JSCs at all time points. Biochemical analysis revealed that samples made with human cells had about 40%-60% of the amount hydroxyproline of native human cartilage, a trend parallel to that observed in the specimens made with swine chondrocytes. The amount of sGAG in the human chondrocyte specimens was about one-and-a-half times the amount in native human cartilage, whereas the amount in the samples made with swine chondrocytes was always less than native cartilage. The biomechanical analysis revealed that the stiffness and tensile of samples made with human cells were in a pattern similar to that seen with swine chondrocytes. This study demonstrates that chondrogenesis using articular chondrocytes from middle-aged adults can be achieved in a predictable and reliable manner similar to that shown in studies using cells from juvenile animals and can form the basis of engineering cartilage with degradable scaffolds in this patient population.

Platelet-Rich Plasma in Orthopaedic Surgery and Sports Medicine: Pearls, Pitfalls, and New Trends in Research

Platelet-rich plasma (PRP) is a novel therapeutic tool in orthopaedic surgery and constitutes a developing area for clinicians and researchers. Increasing numbers of scientific studies are being published on PRP, and there has also been an increased level of awareness in popular culture and mainstream media secondary to recent use of PRP in high-profile athletes. PRP is produced from the patient's own blood by centrifugation, which concentrates platelets along with several bioactive factors that have the ability to promote various aspects of tissue regeneration and protection. These include growth factors such as platelet-derived growth factor (PDGF), transforming growth factor, insulin-like growth factor, and epidermal growth factor, among others. Depending on the method of PRP preparation used, varying compositions of cells and bioactive factors can be found, and only very little is known about the exact regenerative mechanisms of the different PRP components involved. Such crudeness of PRP makes its application fast and easy, while avoiding laborious and time-consuming ex vivo cell processing procedures. The field of PRP clinical and basic science research is growing. There is experimental evidence for positive effects of PRP in the context of soft-tissue healing, ligament and bone regeneration, and inflammation reduction. However, recently emerging prospective randomized clinical trials demonstrate ambiguous results regarding effectiveness with mostly only weak to moderate effects depending on the application. This review outlines the current status of the clinical use of PRP and discusses its risks, pearls and pitfalls, and the direction of future PRP research in the fields of orthopaedic surgery and sports medicine.

The direct anterior approach in hemiarthroplasty for displaced femoral neck fractures

Hip replacement is the most common treatment for displaced femoral neck fractures in the elderly, and minimally invasive surgery is popular in the field of orthopaedic surgery. This study evaluated the outcome of monopolar hemiarthroplasty by the direct anterior approach over a postoperative period up to 2.5 years. A total of 86 patients with displaced femoral neck fractures were included (mean age of 86.5 years). Surviving patients were reviewed three months (retrospectively) and one to 2.5 years (prospectively) after surgery. One-year mortality was 36 %. For all stems, implant positioning with respect to stem alignment, restoration of leg length and femoral offset was correct. Acetabular protrusion was observed in 55 % of the patients one to 2.5 years postoperatively. Subsidence and intraoperative periprosthetic fractures occurred in three patients (3 %) each. All revision stems for postoperative periprosthetic fractures could be implanted using the initial surgical technique without extension of the previous approach. The mean Harris hip score was 85 points at the one to 2.5-year follow-up; 85 % of the patients were satisfied with their hip and 57 % returned to their preoperative level of mobility. Based on these findings, hemiarthroplasty for hip fractures can be performed safely and effectively via the direct anterior approach with good functional outcome and high patient satisfaction.

Ultraviolet light-irradiated photocrosslinkable chitosan hydrogel to prevent bone formation in both rat skull and fibula bone defects

In the field of orthopaedic surgery, an orthopaedic surgeon sometimes requires to suppress excessive bone formation, such as ectopic bone formation, ossifying myositis and radio-ulnar synostosis, etc. Ultraviolet (UV) light irradiation of a photocrosslinkable chitosan (Az-CH-LA) generates an insoluble hydrogel within 30 s. The purpose of this study was to evaluate the ability of the photocrosslinked chitosan hydrogel (PCH) to inhibit bone formation in an experimental model of bone defect. Rat calvarium and fibula were surgically injured and PCH was implanted into the resultant bone defects. The PCH implants significantly prevented bone formation in the bone defects during the 4 and 8 week observation periods. In the PCH-treated defects, fibrous tissues infiltrated by inflammatory cells were formed by day 7, completely filling the bone defects. In addition to these findings, expression of osteocalcin and runt-related gene 2 (RUNX2) mRNA, both markers of bone formation, was lower in the PCH-treated defects than in the controls. In contrast, collagen type 1α2 and α-smooth muscle actin (α-SMA) mRNA levels were significantly higher in the PCH-treated defects after 1 week. PCH stimulated the formation of fibrous tissue in bone defects while inhibiting bone formation. Thus, PCH might be a promising new therapeutic biomaterial for the prevention of bone formation in orthopaedic surgery.

A Modest Proposal for a Clinical Trial on Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction

A Modest Proposal for a Clinical Trial on Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction

Der Hybridoperationssaal

A hybrid operating room must serve the medical needs of different highly specialized disciplines. It integrates interventional techniques for cardiovascular procedures and allows operations in the field of orthopaedic surgery, neurosurgery and maxillofacial surgery. The integration of all steps such as planning, documentation and the procedure itself saves time and precious resources. The best available imaging devices and user interfaces reduce the need for extensive personnel in the OR and facilitate new minimally invasive procedures. The immediate possibility of postoperative control images in CT-like quality enables the surgeon to react to problems during the same procedure without the need for later revision.

An Assessment of Cutting Force for Dental Implant Drilling

Bone drilling is widely used in orthopedics and dental surgery; it is a technically surgical procedure. Recent technological improvements in this area are focused on efforts to reduce forces in bone drilling. The aim of this study was to compare changes in cutting force during dental bone drilling at various drilling conditions and drill tool geometry. In the present in vitro study, dog jaw bone with uniform thickness of cortical bone was used. Cutting force changes were measured during drilling process. Drill jig was designed and manufactured to fix jaw workpiece and mounted on the tool dynamometer to measure cutting force in drilling process. The dental implant drilling tests were conducted at various cutting speeds and feed rates. In this study drilling thrust force was observed 1.5~3.6[N] for MS type implant drilling and 3.1~4.9[N] for conventional high speed steel drilling, respectively. This further research will provide a basic quantitative approach for the timely issue of wide application of implant drilling in dental and orthopedic surgery fields.

Complex Knee Ligament Surgery: Editorial Comment

Over the past 30 years, knee ligament reconstruction has evolved as much as any other within the field of orthopaedic surgery. While, primary ACL reconstruction is now a common procedure, with approximately 100,000 performed per year in the United States, this symposium is intended to examine knee ligament surgery beyond primary ACL reconstruction. Complex knee ligament surgery is varied and challenging, ranging from new multifaceted techniques for ACL reconstruction to complicated multiligament surgery involving reconstruction of all four ligaments (and ligament complexes). Stabilization with external fixation and nerve reconstruction may be required to deal with the sequelae of complex knee ligament injuries. This symposium addresses all of these areas. While primary ACL reconstruction may be considered routine for an experienced knee ligament surgeon, double-bundle ACL reconstruction has been proposed by some as the preferred method. The method remains controversial, particularly in view of its increased complexity compared with single-bundle surgery. One of the studies presented in this symposium explores the issue of early failure in double-bundle reconstructions compared with single-bundle reconstructions. Many patients who have failed ACL reconstruction elect to undergo revision surgery. Revision ACL reconstruction can be challenging and requires broader expertise than primary surgery. In some patients undergoing revision ACL reconstruction, medial or lateral side reconstructions may be appropriate. PCL injuries are less common than ACL injuries but can be more challenging to treat. They are often associated with medial and/or lateral side injuries, as well as ACL injuries. Several papers in this symposium address the biomechanics, evaluation, treatment, and sequelae of multiligament knee injuries. In view of the complexity of multiligament reconstruction, meticulous preoperative planning, attention to surgical detail, and careful postoperative management are required to ensure restoration of function, particularly in athletes with high demands. We believe the articles in this symposium will help those of us who care for these patients by furthering our knowledge relating to the pre- and postoperative care, as well as the surgical management. I would like to thank the authors who worked hard to prepare and revise their manuscripts to meet the high editorial standards of Clinical Orthopaedics and Related Research. It is my hope that these papers will encourage continued and ongoing study of the management of complex knee ligament problems and that some of these injuries may be eliminated through the use of improved prevention programs in the future (Fig. ​(Fig.11). Fig. 1 Dr. Robert G. Marx is shown.