Sarvottam Bajaj

Platelet-Rich Plasma: Where Are We Now and Where Are We Going?

Context: Platelet-rich plasma (PRP) may affect soft tissue healing via growth factors released after platelet degranulation. Because of this potential benefit, clinicians have begun to inject PRP for the treatment of tendon, ligament, muscle, and cartilage injuries and early osteoarthritis. Evidence Acquisition: A PubMed search was performed for studies relating to PRP, growth factors, and soft tissue injuries from 1990 to 2010. Relevant references from these studies were also retrieved. Results: Soft tissue injury is a major source of disability that may often be complicated by prolonged and incomplete recovery. Numerous growth factors may potentiate the healing and regeneration of tendons and ligaments. The potential benefits of biologically enhanced healing processes have led to a recent interest in the use of PRP in orthopaedic sports medicine. There has been widespread anecdotal use of PRP for muscle strains, tendinopathy, and ligament injuries and as a surgical adjuvant to rotator cuff repair, anterior cruciate ligament reconstruction, and meniscal or labral repairs. Although the fascination with this emerging technology has led to a dramatic increase in its use, scientific data supporting this use are still in their infancy. Conclusions: The literature is replete with studies on the basic science of growth factors and their relation to the maintenance, proliferation, and regeneration of various tissues and tissue-derived cells. Despite the promising results of several animal studies, well-controlled human studies are lacking.

Improving Injection Accuracy of the Elbow, Knee, and Shoulder Does Injection Site and Imaging Make a Difference? A Systematic Review

Background: Joint injections and aspirations are used to reduce joint pain and decrease inflammation. The efficacy of these injections is diminished when they are placed inadvertently in the wrong location or compartment. The purpose of this study was to determine whether the use of varying sites or imaging techniques affects the rate of accurate needle placement in aspiration and injection in the shoulder, elbow, and knee. Hypotheses: (1) Accuracy rates of different joint injection sites will demonstrate variability. (2) Injection accuracy rates will be improved when performed with concomitant imaging. Study Design: Systematic review of the literature. Methods: Studies reporting injection accuracy based on image verification were identified through a systematic search of the English literature. Accuracy rates were compared for currently accepted injection sites in the shoulder, elbow, and knee. In addition, accuracy rates with and without imaging of these joints were compared. Results: In the glenohumeral joint, there is a statistically higher accuracy rate with the posterior approach when compared with the anterior approach (85% vs 45%). Injection site selection did not affect accuracy for the subacromial space, acromioclavicular joint, elbow, or knee. The use of imaging improved injection accuracy in the glenohumeral joint (95% vs 79%), subacromial space (100% vs 63%), acromioclavicular joint (100% vs 45%), and knee (99% vs 79%). Conclusion: Injection accuracy rates are significantly higher for the posterior approach compared with the anterior approach for the glenohumeral joint. Similarly, the accuracy rates are also higher when imaging is used in conjunction with injection of the glenohumeral joint, subacromial space, acromioclavicular joint, and knee.

Autologous chondrocyte implantation: an overview of technique and outcomes

Articular cartilage is susceptible to damage; however, it has limited capacity for repair. Damage can lead to persistent symptoms including pain, swelling, and loss of function and may ultimately progress to symptomatic degeneration of the joint. To restore function and minimize symptoms, many advocate surgical intervention in selected candidates, which can range from arthroscopic debridement to restorative procedures depending on patient and lesion characteristics. Autologous Chondrocyte Implantation (ACI) is a two‐stage, typically second‐line intervention where cultured autologous chondrocytes are used with the aim of resurfacing symptomatic chondral defects with hyaline or hyaline‐like cartilage. Careful patient selection is important. We present an overview of this procedure including indications and contraindications, surgical technique, and post‐operative management. A review of published ACI outcomes is then presented.

The Basic Science and Surgical Treatment Options for Articular Cartilage Injuries of the Knee

The complex structure of articular cartilage allows for diverse knee function throughout range of motion and weight bearing. However, disruption to the structural integrity of the articular surface can cause significant morbidity. Due to an inherently poor regenerative capacity, articular cartilage defects present a treatment challenge for physicians and therapists. For many patients, a trial of nonsurgical treatment options is paramount prior to surgical intervention. In instances of failed conservative treatment, patients can undergo an array of palliative, restorative, or reparative surgical procedures to treat these lesions. Palliative methods include debridement and lavage, while restorative techniques include marrow stimulation. For larger lesions involving subchondral bone, reparative procedures such as osteochondral grafting or autologous chondrocyte implantation are considered. Clinical success not only depends on the surgical techniques but also requires strict adherence to rehabilitation guidelines. The purpose of this article is to review the basic science of articular cartilage and to provide an overview of the procedures currently performed at our institution for patients presenting with symptomatic cartilage lesions.

Protective effect of P188 in the model of acute trauma to human ankle cartilage: the mechanism of action.

Objective: Because P188 poloxamer is effective in promoting cell survival in models of acute trauma, the objectives were to understand the mechanism of its action focusing on glycogen synthase kinase-3 (GSK3) activation, interleukin-6 (IL-6), and p38 signaling. Design: Sixteen normal human tali were impacted using a 4-mm diameter indenter with an impulse of 1 Ns. Eight-millimeter cartilage plugs containing the 4-mm impacted core and 4-mm adjacent nonimpacted ring were removed and cultured with or without P188. Cell lysates were analyzed using Western blots with antibodies against total and phosphorylated extracellular signal-regulated protein kinase (ERK), c-Jun NH(2)-terminal kinase (JNK), p38, ATF-2, GSK3, Stat1, and Stat3. Additional tests were performed with the p38 inhibitor (p38i) SB203580. Results: Studied pathways were activated after impaction with the peak of activity at 1 hour. P188 completely attenuated phosphorylation of Stat1 and ATF-2 and inhibited p38, Stat3, JNK, ERK, and GSK3. The p38i partially offset phosphorylation of Stat3, GSK3, and ERK suggesting a role of p38 in these three pathways. Additionally, the p38i improved cell survival (P = 0.053) and reduced apoptosis (by approximately 20%, P = 0.046, versus almost 40% by P188), thus confirming that P188 acts (at least in part) through the p38 pathway. Conclusion: Our results report a novel mechanism through which P188 exerts its protective effects on cartilage in the model of acute injury. In addition to its effect on cellular membrane, P188 affects stress-related p38 signaling, apoptosis-related GSK3, and inflammation-related IL-6 signaling. Taken together, these findings suggest that P188 alone or in combination with proanabolic agents may have a therapeutic potential in preventing progressive cartilage degeneration and the development of posttraumatic osteoarthritis.

Long-Term Evaluation of Autologous Chondrocyte Implantation: Minimum 7-Year Follow-Up

Purpose: The purpose of this study was to report the clinical outcomes of autologous chondrocyte implantation (ACI) procedures performed by a single orthopedic surgeon at a minimum of 7 years follow-up. Methods: A retrospective review of prospectively collected data was performed on 29 patients who underwent ACI of the knee between the years of 1998 and 2003. Prospective data were collected to assess changes in standardized outcome measures preoperatively and 2, 4, and 7 years postoperatively. All patients enrolled in the study were also recruited to undergo physical examination when possible. Results: The final cohort consisted of 29 patients with a mean final follow-up time of 8.40 years (range = 7.14-10.88 years). Comparing preoperative scores to 7-year postoperative values, the mean International Knee Documentation Committee (IKDC) score improved from 39.80 to 59.24 (P < 0.001), mean Tegner-Lysholm score increased from 48.07 to 74.17 (P < 0.001), SF-12 physical score improved from 40.38 to 48.66 (P < 0.001), and SF-12 mental score improved from 44.14 to 48.98 (P < 0.05). Significant improvement occurred in Knee Injury and Osteoarthritis Outcome Score (KOOS) pain (56.03 to 80.36), symptoms (54.19 to 74.75), activities of daily living (72.01 to 85.90), sports (23.34 to 55.34), and quality of life (24.56 to 56.03) (P < 0.001). In addition, 7-year postoperative scores were at or near levels seen at 2 years (mean = 2.16; range = 0.94-4.03 years) and 4 years (mean = 4.43; range = 2.16-5.88 years) postoperatively, reflecting durable improvement. Subjectively, on a scale of 1 to 10 (10 being completely satisfied), the mean postoperative satisfaction rate was 8.14. Additionally, 88.9% of the patients would elect to have this surgery again if the same problem was to occur in the contralateral joint. Conclusions: The results of ACI in patients who present with symptomatic, full-thickness chondral defects remain durable at a minimum of 7-year follow-up with persistent, high levels of patient satisfaction. Level of Evidence: Case series; Level of evidence, IV.

Salvage of contaminated osteochondral allografts: the effects of chlorhexidine on human articular chondrocyte viability.

Background: Because chondrocyte viability is imperative for successful osteochondral allograft transplantation, sterilization techniques must provide antimicrobial effects with minimal cartilage toxicity. Chlorhexidine gluconate (CHG) is an effective disinfectant; however, its use with human articular cartilage requires further investigation. Purpose: To determine the maximal chlorhexidine concentration that does not affect chondrocyte viability in allografts and to determine whether this concentration effectively sterilizes contaminated osteoarticular grafts. Study Design: Controlled laboratory study. Methods: Osteochondral plugs were subjected to pulse lavage with 1-L solutions of 0.002%, 0.01%, 0.05%, and 0.25% CHG and cultured for 0, 1, 2, and 7 days in media of 10% fetal bovine serum and antibiotics. Chondrocyte viability was determined via LIVE/DEAD Viability Assay. Plugs were contaminated with Staphylococcus aureus and randomized to 4 treatment groups. One group was not contaminated; the 3 others were contaminated and received no treatment, saline pulse lavage, or saline pulse lavage with 0.002% CHG. Serial dilutions were plated and colony-forming units assessed. Results: The control group and the 0.002% CHG group showed similar cell viability, ranging from 67% ± 4% to 81% ± 22% (mean ± SD) at all time points. In the 0.01% CHG group, cell viability was reduced in comparison with control by 2-fold at day 2 and remained until day 7 (P < .01). The 0.05% and 0.25% CHG groups showed a 2-fold reduction in cell viability at day 1 (P < .01). At day 7, cell viability was reduced to 15% ± 18% (4-fold decrease) for the 0.05% CHG group and 10% ± 19% (6-fold decrease) for the 0.25% CHG group (P < .01). Contaminated grafts treated with 0.002% CHG demonstrated no colony-forming units. Conclusion: Pulse lavage with 0.002% CHG does not cause significant cell death within 7 days after exposure, while CHG at concentrations >0.002% significantly decreases chondrocyte viability within 1 to 2 days after exposure and should therefore not be used for disinfection of osteochondral allograft. Pulse lavage does not affect chondrocyte viability but cannot be used in isolation to sterilize contaminated fragments. Overall, 0.002% CHG was shown to effectively decontaminate osteoarticular fragments. Clinical Relevance: This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability.

Failed Cartilage Repair

The management of traumatic and degenerative cartilage lesions is a known challenge given the limited vascularity and lack of pluripotent cells that contribute to the tissue’s inherently poor regenerative capacity. Many surgical techniques have been described in an effort to palliate symptoms, promote substitute tissue growth, and/or restore normal hyaline cartilage. Surgical failure of these techniques, however, may occur when the patient experiences incomplete or recurrent symptoms, or an inability to return to his or her desired activity level. Unfortunately, when all techniques are considered in aggregate, there remains a clinical failure rate that approaches 25% in most series. Technical error, graft dislodgment, graft resorption, and the failure to recognize concomitant injury leading to premature graft destruction are common causes for surgical failure. Successful revision articular cartilage repair requires a thorough evaluation of comorbid conditions such as ligament instability, malalignment, and meniscal deficiency. These complications, left untreated, can have a detrimental effect on the cartilage repair procedure because of abnormal shear stress, increased contact pressure, and decreased contact area.

Cartilage Restoration in the Patellofemoral Joint

The treatment of patellofemoral (PF) articular cartilage pathology is difficult because the pathology is multifactorial and symptoms related to the cartilage portion of the problem are expressed through noncartilaginous tissue. Since cartilage is aneural, the symptoms from the cartilage defects are mediated through the mechanical effects on bone and by cartilage debris that causes noxious stimulation of soft tissues. A systematic history, thorough physical examination, and appropriate imaging studies are essential to assign a portion of the patient’s symptoms to the cartilage pathology. A successful outcome for patellofemoral articular cartilage restoration requires treatment of each individual component of the multifactorial pathology, and with careful patient selection and comprehensive patient and knee specific surgical management, it is possible for cartilage restoration in the patellofemoral compartment to have a success rate similar to the tibiofemoral compartment.

Anteromedial Tibial Tubercle Osteotomy (Fulkerson Osteotomy)

Multiple case series have reported outcomes of the AMZ procedures. Despite the heterogeneity in outcome measurements, results demonstrate high percentages of excellent and good results and improvements in objective, subjective and functional measures. Attention to details related to surgical planning and properly managing patient expectations is most likely to lead to good or excellent results. Newer techniques (i.e., the T3 system) allow the surgeon to objectively determine the inclination of the osteotomy to properly restore patellofemoral mechanics based upon the preoperative planning.