Nahum Rosenberg

Comparison of intraarticular injection of depot corticosteroid and hyaluronic acid for treatment of degenerative trapeziometacarpal joints.

Background:Trapeziometacarpal joint arthritis is a disabling condition presenting with pain at the base of the thumb causing impairment of hand function. Nonoperative treatment at an early stage includes intraarticular steroid injection. Although this treatment may bring about prompt symptomatic relief, its efficacy is unpredictable. Objectives:There is previous evidence that injection of sodium hyaluronate is effective and safe in the treatment of knee arthritis. We proposed that intraarticular injection of sodium hyaluronate, for the symptomatic treatment of trapeziometacarpal joint arthritis, could provide symptomatic relief without the adverse effects of steroids. Methods:Fifty-two patients with trapeziometacarpal joint grade II arthritis were randomized prospectively either for methylprednisolone or hyaluronate intraarticular injections. Initial evaluation included an estimation of pain, grip, pinch strengths and the functional Purdue Pegboard Test (PPT). This evaluation was repeated after 1, 3, and 6 months and statistically compared with the initial evaluation. Results:In both groups, the intraarticular injection produced a relief of pain after 1 month. Grip strength improved significantly in the group treated by the steroid during the whole evaluation period. The patients treated by hyaluronate showed improvement in grip strength after 6 months and in the pinch and the PPT after 3 months. Conclusions:Steroids and hyaluronate injections were found effective in reducing pain. Hyaluronate was more effective in the improvement of some aspects of fine hand function.

Surgical treatment of painful neuroma in medial antebrachial cutaneous nerve.

The branches of the medial antebrachial cutaneous nerve (MACN) are located at the medial site of the elbow. The MACN, especially the posterior branches, may be injured or transected during cubital tunnel surgery or other medial approaches to the elbow. Damage to the nerve can cause a neuroma, which leads to disabling pain and restriction of elbow movement. The initial treatment of the neuroma is nonsurgical, and includes local massage, desensitization, physiotherapy, and systemic medication. If after 6 months of these nonsurgical treatments there is no improvement, surgery is indicated. The authors report their experience with 12 patients treated surgically for painful neuroma by high resection of the proximal end or its implantation into the triceps muscle. After surgery there was a high success rate of pain relief and functional improvement in both elbow movement and handgrip strength.

Osteoblasts in Bone Physiology—Mini Review

Bone structural integrity and shape are maintained by removal of old matrix by osteoclasts and in-situ synthesis of new bone by osteoblasts. These cells comprise the basic multicellular unit (BMU). Bone mass maintenance is determined by the net anabolic activity of the BMU, when the matrix elaboration of the osteoblasts equals or exceeds the bone resorption by the osteoclasts. The normal function of the BMU causes a continuous remodeling process of the bone, with deposition of bony matrix (osteoid) along the vectors of the generated force by gravity and attached muscle activity. The osteoblasts are derived from mesenchymal stem cells (MSCs). Circulating hormones and locally produced cytokines and growth factors modulate the replication and differentiation of osteoclast and osteoblast progenitors. The appropriate number of the osteoblasts in the BMU is determined by the differentiation of the precursor bone-marrow stem cells into mature osteoblasts, their proliferation with subsequent maturation into metabolically active osteocytes, and osteoblast degradation by apoptosis. Thus, the two crucial points to target when planning to control the osteoblast population are the processes of cell proliferation and apoptosis, which are regulated by cellular hedgehog and Wnt pathways that involve humoral and mechanical stimulations. Osteoblasts regulate both bone matrix synthesis and mineralization directly by their own synthetic activities, and bone resorption indirectly by its paracrinic effects on osteoclasts. The overall synthetic and regulatory activities of osteoblasts govern bone tissue integrity and shape.

Comparison of two methods for the evaluation of treatment in medial epicondylitis: pain estimation vs grip strength measurements

IntroductionDetermination of a precise and reproducible diagnostic tool for the evaluation of patients with medial epicondylitis (ME) is important for an effective follow-up. The commonly suggested use of grip strength measurements with a hand dynamometer is not always easily available and may be affected by the patient’s compliance. We propose that pain estimation based on the visual analog scale can be considered for this purpose as well because it addresses the painful degenerative lesion in the common flexor origin, which is the basic pathological process in ME.Materials and methodsWe analyzed and compared 237 different sets of measurements of grip strengths and pain evaluation, according to the visual analog scale, in 79 patients with ME. For the purpose of this comparison, we developed a qualitative grading system based on the statistical data of the grip strength values in the normal population.ResultsHigh dependency between the graded pain evaluation and measured grip strength was found.ConclusionWe suggest that evaluation of patients with ME according to the proposed grading method of pain evaluation is as accurate as grip strength measurements.

Periprosthetic Infection Following Total Knee Arthroplasty

One of the most devastating complications of prosthetic knee arthroplasty is a periprosthetic infection. This complication occurs in 1-2% of knee arthroplasties [1,2] and can exceed 4% in immunocompromized individuals [3] and 7% after revision surgery [4]. Prosthetic infection leads to loosening of the implant, [5,6]. In this circumstances revision surgery is required. Because of the diversity of the clinical presentation, i.e. early, intermediate or late infection [1], different surgical methods to treat infected knee prostheses were developed [5,6]. Sever‐ al treatment methods became well accepted but others are still controversial. In the present review we intend to describe mainly the diagnostic tools for detection of infection and com‐ monly used treatment methods in failed total knee arthroplasty due to infection, with spe‐ cial emphasis on the surgical techniques. Additionally we will describe some trends for the future improvement of the treatment modalities.

Determination of biophysical parameters for enhancement of human osteoblast proliferation by mechanical vibration in the infrasonic frequency range

Experimental methods for studying an enhancement of osteoblast proliferation in vitro provide tools for the research of biochemical processes involved in bone turnover in vivo. Some of the current methods used for this purpose are based on the ability of the osteoblasts to enhance proliferation by mechanical stimulation. We describe an experimental approach of biomechanical stimulation of cultured human osteoblast-like cells by vibration. This method is based on the specially designed controlled vibration setup that consists of an electric actuator, with horizontally mounted well plate containing cell cultures. Previously this method found to be effective to enhance cell proliferation, but the exact mechanical parameters of effective vibration were elusive. The current low friction system for mechanical stimulation of osteoblast-like cells in vitro provides recording of narrow range mechanical parameters in the infrasonic spectrum. We exposed human osteoblast-like cells in explant monolayer culture to mechanical vibration in the 10-70Hz range of frequencies and found that 50-70 Hz of vibration frequency is optimal for inducing osteoblast proliferation that was deduced from interrelation between unchanged cell number in culture samples with significant decrease in cell death rate (decreased LDH activity in culture media, p<.05) and with parallel decrease of their maturation level (p<.01). In this report we determined the optimal mechanical parameters and excitation protocol for induction of osteoblast proliferation in vitro by using a tunable and versatile mechanical platform, which can be used in the research of cell mechanotransduction.Experimental methods for studying an enhancement of osteoblast proliferation in vitro provide tools for the research of biochemical processes involved in bone turnover in vivo. Some of the current methods used for this purpose are based on the ability of the osteoblasts to enhance proliferation by mechanical stimulation. We describe an experimental approach of biomechanical stimulation of cultured human osteoblast-like cells by vibration. This method is based on the specially designed controlled vibration setup that consists of an electric actuator, with horizontally mounted well plate containing cell cultures. Previously this method found to be effective to enhance cell proliferation, but the exact mechanical parameters of effective vibration were elusive. The current low friction system for mechanical stimulation of osteoblast-like cells in vitro provides recording of narrow range mechanical parameters in the infrasonic spectrum. We exposed human osteoblast-like cells in explant monolayer culture to mechanical vibration in the 10-70Hz range of frequencies and found that 50-70 Hz of vibration frequency is optimal for inducing osteoblast proliferation that was deduced from interrelation between unchanged cell number in culture samples with significant decrease in cell death rate (decreased LDH activity in culture media, p<.05) and with parallel decrease of their maturation level (p<.01). In this report we determined the optimal mechanical parameters and excitation protocol for induction of osteoblast proliferation in vitro by using a tunable and versatile mechanical platform, which can be used in the research of cell mechanotransduction .

Experimental In Vitro Methods for Research of Mechanotransduction in Human Osteoblasts

Bone matrix is generated and organized according to the direction of mechanical force, e.g., following muscular contraction, impact with supporting surface and gravity. Cellular mechanotransduction from outer milieu, which is a biochemical expression of the external mechanical force via cellular pathways, determines the three dimensional structure of bone following interactions between its generation and resorption, i.e., remodeling and repair process by interaction between osteoblast and osteoclast activities. Of the latter two type of cells the osteoblast governs this complex process, partially following the external mechanical effect. Therefore understanding and recognizing of the nature of the cellular pathways in osteoblast mechnotransduction might reveal new therapeutic methods in numerous disabling bone pathologies due to the loss of bone mass or the loss of its structural integrity.

Quntative Expression of Cell Death by LDH Activity

We hypothesize that a universal quantitative relation exists between the number of necrotic cells in culture and LDH activity in culture media. Previously this relation was found in immortalised cell lines. We hypothesized that similar correlation exists in normal cells of human origin. We investigated cultured human oseoblast-like cells. LDH activity in the media of cultured samples (n=8) was determined by 340 nm wavelength spectrophotometry. Cell viability was determined using automated cell counter. Significant and high correlation was found between LDH activity in culture media and the numbers of non-viable cells (n=8, CC – 0.95, power – 0.984, SE= 13,920, p< 0.001). These findings support the use of media LDH activity measurements for estimation of cell death rate in culture without the need of a major manipulation of the cultured cells.

Glenoid Loosening in Total Shoulder Arthroplasty

Inflammatory or degenerative processes in glenohumeral joint lead to pain and restriction of movements of the shoulder. Prosthetic replacement of the glenohumeral joint has gained in popularity because of its efficacy in relieving pain. The pioneering successful prostheses for total shoulder arthroplasty (TSA) have been based on an unconstrained de‐ sign, i.e. a metal spherical head component fixed to a metal intramedullary stem articulat‐ ing with a high-density polyethylene socket. These components are stabilized in the adjacent bone using polymethylmethacrylate (PMMA) bone cement [1]. The most impor‐ tant cause for failure of the cemented prostheses is related to the glenoid component, with a 0.01-6% rate of loosening [2, 3, 4].

Mobile Bearing Concept in Knee Arthroplasty

The rationale for mobile bearing design of knee replacement prosthesis is to increase its survival by reducing the rate of aseptic loosening and to improve the range of movement of the treated knee. The theoretical basis for the achievement of the first goal is the expected lower rates of the polyethylene insert wear in the mobile design in comparison to a fixed design, due to lower contact and constraint forces. A better range of movements following mobile bearing arthroplasty is expected as the result of additional moving surface between to fixed planes at the ends of the articulating bones, allowing mobility with congruency.These expected advantages of the mobile bearing design should be judged cautiously since the initial mobile bearing implants caused higher rates of breakage and disarrangement of the polyethylene inserts, when the implantation method wasn’t strictly followed. In order to resolve these technical problems the rotating platform mobile prosthesis was developed. Mobile bearing concept was implemented in a three compartment replacement prostheses and also in unicompartamental designs, especially for the medial compartment of the knee. Currently, following the more than two decades of the rising experience with implantation of a large number of mobile bearing prostheses, there is a significant amount of data for evaluation of the survival of these prosthetic designs. In order to declare on their higher expected efficiency these implants should show higher than 96-97% of ten year clinical survival, which should remain relatively stable up to 20 years of follow up, as reported in the several of fixed bearing designs. Unfortunately this data is not readily available, because only few well designed survivorship reports on mobile knee implants have been published yet. Furthermore the published data failed to provide a clear evidence of the superiority of mobile bearing design. The endoprosthetic arthroplasty is the most popular surgical modality for treatment of advanced knee joint disease, either degenerative or inflammatory. The reason for this clinical trend is the ability to reduce pain and to restore the patient’s ability to walk.