Eric J. Strauss

The Role of Growth Factors in Cartilage Repair

BackgroundFull-thickness chondral defects and early osteoarthritis continue to present major challenges for the patient and the orthopaedic surgeon as a result of the limited healing potential of articular cartilage. The use of bioactive growth factors is under consideration as a potential therapy to enhance healing of chondral injuries and modify the arthritic disease process.Questions/purposesWe reviewed the role of growth factors in articular cartilage repair and identified specific growth factors and combinations of growth factors that have the capacity to improve cartilage regeneration. Additionally, we discuss the potential use of platelet-rich plasma, autologous-conditioned serum, and bone marrow concentrate preparations as methods of combined growth factor delivery.MethodsA PubMed search was performed using key words cartilage or chondrocyte alone and in combination with growth factor. The search was open for original manuscripts and review papers and open for all dates. From these searches we selected manuscripts investigating the effects of growth factors on extracellular matrix synthesis and excluded those investigating molecular mechanisms of action.ResultsBy modulating the local microenvironment, the anabolic and anticatabolic effects of a variety of growth factors have demonstrated potential in both in vitro and animal studies of cartilage injury and repair. Members of the transforming growth factor-β superfamily, fibroblast growth factor family, insulin-like growth factor-I, and platelet-derived growth factor have all been investigated as possible treatment augments in the management of chondral injuries and early arthritis.ConclusionsThe application of growth factors in the treatment of local cartilage defects as well as osteoarthritis appears promising; however, further research is needed at both the basic science and clinical levels before routine application.

The evolution of locked plates

Our purpose is to review the history of locked plates and the current recommendations for the use of those devices and to look toward future trends in the clinical application of locked plates. We will discuss (1) the impetus for the locked (fixed-angle) plate design, (2) current indications and design trends, (3) the latest clinical and biomechanical data, (4) shortcomings of locked (fixed-angle) plates, and (5) future applications and directions for locked (fixed-angle) plates. Since their initial introduction in the late nineteenth century and their subsequent popularization by Danis1-3 and the Arbeitsgemeinschaft fur Osteosynthesefragen (AO) group in the 1960s, conventional nonlocked plates have proven, over time, to successfully stabilize many types of fractures and osteotomy sites. The plate-screw-bone construct must resist physiological loads to allow fracture union by limiting fracture gap stress, provide sufficient stability to permit early limb motion, and not fail before fracture union occurs. Additionally, for optimal clinical results, disruption of the bone blood supply by the plate-screw-bone construct should be minimized. To accomplish this goal, there should be minimal operative dissection and periosteal contact to promote bone union4,5. Ideally, the plate-screw-bone construct will permit the restoration of the mechanical limb alignment and reestablish joint congruity to within <2 mm2,6,7. Finally, to be successful, plate fixation must provide reproducible results, must be simple to perform, and must have broad clinical applicability. Fixation with conventional compression plates, although for the most part successful, has its limitations. Figure 1 demonstrates one attempt to counter the limitations associated with the use of conventional nonlocked plates. To achieve fracture stability, the axial, torsional, and three-point bending forces must be neutralized (Fig. 2). With the use of conventional nonlocked plates, force friction between the plate and the bone counters …

Long Head of the Biceps Tendinopathy: Diagnosis and Management

&NA; Tendinopathy of the long head of the biceps brachii encompasses a spectrum of pathology ranging from inflammatory tendinitis to degenerative tendinosis. Disorders of the long head of the biceps often occur in conjunction with other shoulder pathology. A thorough patient history, physical examination, and radiographic evaluation are necessary for diagnosis. Nonsurgical management, including rest, nonsteroidal anti‐inflammatory drugs, physical therapy, and injections, is attempted first in patients with mild disease. Surgical management is indicated for refractory or severe disease. In addition to simple biceps tenotomy, a variety of tenodesis techniques has been described. Open biceps tenodesis has been used historically. However, promising results have recently been reported with arthroscopic tenodesis.

Greater Trochanteric Pain Syndrome

Originally defined as “tenderness to palpation over the greater trochanter with the patient in the side-lying position,” greater trochanteric pain syndrome (GTPS) as a clinical entity, has expanded to include a number of disorders of the lateral, peritrochanteric space of the hip, including trochanteric bursitis, tears of the gluteus medius and minimus and external coxa saltans (snapping hip). Typically presenting with pain and reproducible tenderness in the region of the greater trochanter, buttock, or lateral thigh, GTPS is relatively common, reported to affect between 10% and 25% of the general population. Secondary to the relative paucity of information available on the diagnosis and management of components of GTPS, the presence of these pathologic entities may be underrecognized, leading to extensive workups and delays in appropriate treatment. This article aims to review the present understanding of the lesions that comprise GTPS, discussing the relevant anatomy, diagnostic workup and recommended treatment for trochanteric bursitis, gluteus medius and minimus tears, and external coxa saltans.

Hyaluronic Acid Viscosupplementation and Osteoarthritis Current Uses and Future Directions

Intra-articular hyaluronic acid viscosupplementation is gaining popularity as a treatment option in the nonoperative management of patients with osteoarthritis. Recent clinical studies have demonstrated that the anti-inflammatory, anabolic, and chondroprotective actions of hyaluronic acid reduce pain and improve patient function. With evidence mounting in support of the efficacy of this treatment modality for patients with osteoarthritis, its potential use in additional patient populations and for other pathologies affecting the knee is being investigated. The current article reviews the use of intra-articular hyaluronic acid viscosupplementation in the management of knee osteoarthritis and presents the potential for expanding its indications for other joints and alternative patient subpopulations. Additionally, future directions for the use of hyaluronic acid and areas of active research are discussed.

The arthroscopic management of partial-thickness rotator cuff tears: A systematic review of the literature

PURPOSE There is currently limited information available in the orthopaedic surgery literature regarding the appropriate management of symptomatic partial-thickness rotator cuff tears. METHODS A systematic search was performed in PubMed, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and the Cochrane Central Register of Controlled Trials of all published literature pertaining to the arthroscopic management of partial-thickness rotator cuff tears. Inclusion criteria were all studies that reported clinical outcomes after arthroscopic treatment of both articular-sided and bursal-sided lesions using a validated outcome scoring system and a minimum of 12 months of follow-up. Data abstracted from the selected studies included tear type and location (articular v bursal sided), treatment approach, postoperative rehabilitation protocol, outcome scores, patient satisfaction, and postoperative imaging results. RESULTS Sixteen studies met the inclusion criteria and were included for the final analysis. Seven of the studies treated partial-thickness rotator cuff tears with debridement with or without an associated subacromial decompression, 3 performed a takedown and repair, 5 used a transtendon repair technique, and 1 used a transosseous repair method. Among the 16 studies reviewed, excellent postoperative outcomes were reported in 28.7% to 93% of patients treated. In all 12 studies with available preoperative baseline data, treatment resulted in significant improvement in shoulder symptoms and function. For high-grade lesions, the data support arthroscopic takedown and repair, transtendon repairs, and transosseous repairs, with all 3 techniques providing a high percentage of excellent results. Debridement of partial-thickness tears of less than 50% of the tendons thickness with or without a concomitant acromioplasty also results in good to excellent surgical outcomes; however, a 6.5% to 34.6% incidence of progression to full-thickness tears is present. CONCLUSIONS This systematic review of 16 clinical studies showed that significant variation is present in the results obtained after the arthroscopic management of partial-thickness rotator cuff tears. What can be supported by the available data is that tears that involve less than 50% of the tendon can be treated with good results by debridement of the tendon with or without a formal acromioplasty, although subsequent tear progression may occur. When the tear is greater than 50%, surgical intervention focusing on repair has been successful. There is no evidence to suggest a differential in outcome for tear completion and repair versus transtendon repair of these lesions because both methods have been shown to result in favorable outcomes. LEVEL OF EVIDENCE Level IV, systematic review of Level IV studies.

Can Anatomic Femoral Tunnel Placement Be Achieved Using a Transtibial Technique for Hamstring Anterior Cruciate Ligament Reconstruction

Background: Recent studies have emphasized the importance of anatomic tunnel placement during anterior cruciate ligament (ACL) reconstruction in an effort to restore normal knee kinematics and stability. Secondary to the constraints imposed by a coupled drilling technique, the ability to achieve an anatomic femoral tunnel during transtibial hamstring ACL reconstruction may be limited. Hypothesis: The size limitations imposed by the small-diameter tibial tunnel used in hamstring ACL reconstruction would preclude the ability to place an anatomic femoral tunnel. Study Design: Descriptive laboratory study. Methods: In a descriptive laboratory study, fresh-frozen human cadaveric knees fixed at 90° of flexion were dissected to expose the centers of the native femoral and tibial ACL insertions. The geometry and location of each insertion were evaluated. Using a standardized starting point, tibial tunnels were drilled to the center of the tibial insertion using an 8-mm reamer. Next, a 6-mm over-the-top guide was used to position as close as possible to the anatomic femoral ACL insertion on the lateral wall, and femoral tunnels were drilled with the 8-mm reamer. For each tunnel, the location, geometry, and percentage overlap with the native insertion site were evaluated using a 3-dimensional laser scanner. Results: The reamed tibial tunnel was central within the insertion site, occupying 40.4% ± 2.0% of the native tibial insertion. Transtibial drilling resulted in femoral tunnels that were superior and posterior compared with the native femoral insertion. Thefemoral tunnel had a mean ± SD overlap of 30.0% ± 12.6% with the femoral insertion, with the center of the tunnel 7.6± 0.5 mm from the center of the native ACL femoral insertion. Conclusion: Based on our data using our specific starting point, during hamstring ACL reconstructions, the constraints imposed by a coupled drilling technique result in nonanatomic femoral tunnels that are superior and posterior to the native femoral insertion. Clinical Relevance: Anatomic femoral tunnel placement during hamstring ACL reconstructions may not be possible using a coupled, transtibial drilling approach.

The glenoid in shoulder arthroplasty.

Total shoulder arthroplasty is a common treatment for glenohumeral arthritis. One of the most common failure modes of total shoulder arthroplasty is glenoid loosening, causing postoperative pain, limitation of function, and potentially, the need for revision surgery. The literature has devoted considerable attention to the design of the glenoid component; efforts to better understand the biomechanics of the reconstructed glenohumeral joint and identify factors that contribute to glenoid component loosening are ongoing. This article reviews the current state of knowledge about the glenoid in total shoulder arthroplasty, summarizing the anatomic parameters of the intact glenoid, variations in component design and fixation, the mechanisms of glenoid loosening, the outcomes of revision surgery in the treatment of glenoid component failure, and alternative treatments for younger patients.

Does obesity influence the outcome after the operative treatment of ankle fractures

Many orthopaedic surgeons believe that obese patients have a higher rate of peri-operative complications and a worse functional outcome than non-obese patients. There is, however, inconsistency in the literature supporting this notion. This study was performed to evaluate the effect of body mass index (BMI) on injury characteristics, the incidence of complications, and the functional outcome after the operative management of unstable ankle fractures. We retrospectively reviewed 279 patients (99 obese (BMI > or = 30) and 180 non-obese (BMI < 30) patients who underwent surgical fixation of an unstable fracture of the ankle. We found that obese patients had a higher number of medical co-morbidities, and more Orthopaedic Trauma Association type B and C fracture types than non-obese patients. At two years from the time of injury, however, the presence of obesity did not affect the incidence of complications, the time to fracture union or the level of function. These findings suggest that obese patients should be treated in line with standard procedures, keeping in mind any known associated medical co-morbidities.

Biochemical and Biomechanical Properties of Lesion and Adjacent Articular Cartilage after Chondral Defect Repair in an Equine Model

Background Chondral defects may lead to degradative changes in the surrounding cartilage, predisposing patients to developing osteoarthritis. Purpose To quantify changes in the biomechanical and biochemical properties of the articular cartilage adjacent to chondral defects after experimental defect repair. Study Design Controlled laboratory study. Methods Specimens were harvested from tissue within (lesion), immediately adjacent to, and at a distance from (remote area) a full-thickness cartilage defect 8 months after cartilage repair with genetically modified chondrocytes expressing insulin-like growth factor-I or unmodified, control chondrocytes. Biomechanical properties, including instantaneous Youngs and equilibrium aggregate moduli, were determined by confined compression testing. Biochemical properties, such as water and proteoglycan content, were also measured. Results The instantaneous Youngs modulus, equilibrium modulus, and proteoglycan content increased, whereas water content decreased with increasing distance from the repaired lesion. The instantaneous Youngs and equilibrium moduli of the adjacent articular cartilage were 80% and 50% that of remote area samples, respectively, whereas water content increased 0.9% and proteoglycan content was decreased by 35%. No significant changes in biomechanical and biochemical properties were found either in the lesion tissue or in adjacent cartilage with genetic modification of the chondrocytes. Conclusion Articular cartilage adjacent to repaired chondral defects showed significant remodeling 8 months after chondral defect repair, regardless of whether genetically modified or unmodified cells were implanted. Clinical Relevance Changes in the biochemical and biomechanical properties of articular cartilage adjacent to repaired chondral defects may represent remodeling as part of an adaptive process or degeneration secondary to an altered distribution of joint forces. Quantification of these changes could provide important parameters for assessing progress after operative chondral defect repair.