Riley J. Williams

The Effect of Ciprofloxacin On Tendon, Paratenon, and Capsular Fibroblast Metabolism

The pathologic mechanisms underlying fluoroquinolone-induced tendinopathy are poorly understood. The observed incidence of tendinitis and tendon rupture in patients treated with ciprofloxacin hydrochloride suggests that the fluoroquinolone antibiotics alter tendon fibroblast metabolism. The purpose of this study was to examine the effect of ciprofloxacin on fibroblast metabolism in vitro. Canine Achilles tendon, paratenon, and shoulder capsule specimens were maintained in culture with ciprofloxacin (5, 10, or 50 g/ml). Fibroblast proliferation, collagen synthesis, proteoglycan synthesis, and matrix-degrading activity were analyzed. Incubation of Achilles tendon, Achilles paratenon, and shoulder capsule fibroblasts with ciprofloxacin resulted in a statistically significant 66% to 68% decrease in cell proliferation compared with control cells at day 3 in culture. Ciprofloxacin caused a statistically significant 36% to 48% decrease in collagen synthesis compared with controls in all fibroblast cultures. Ciprofloxacin caused a statistically significant 14% to 60% decrease in proteoglycan synthesis in all fibroblast cell lines. Compared with unstimulated control fibroblasts, culture media from Achilles tendon, paratenon, and shoulder capsule cells that were exposed to ciprofloxacin demonstrated statistically significant increases in matrix-degrading proteolytic activity after 72 hours in culture. This study demonstrates that ciprofloxacin stimulates matrix-degrading protease activity from fibroblasts and that it exerts an inhibitory effect on fibroblast metabolism. The increase in protease activity and the inhibition of both cell proliferation and the synthesis of matrix ground substance may contribute to the clinically described tendinopathies associated with ciprofloxacin therapy.

Magnetic Resonance Imaging and Clinical Evaluation of Patellar Resurfacing With Press-Fit Osteochondral Autograft Plugs

BACKGROUNDnAutologous osteochondral transplantation (AOT) has been successfully used in the femoral condyle and trochlea and is an attractive treatment option for full-thickness patellar cartilage lesions.nnnHYPOTHESISnPatients treated with AOT for the repair of symptomatic, isolated patellar cartilage lesions will demonstrate improvement in functional outcomes and postoperative magnetic resonance imaging appearance.nnnSTUDY DESIGNnCase series; Level of evidence, 4.nnnMETHODSnBetween 2002 and 2006, patients with focal patellar cartilage lesions treated with AOT were prospectively followed. The mean age at the time of surgery was 30 years. Clinical assessment was performed with the International Knee Documentation Committee (IKDC), activities of daily living of the Knee Outcome Survey (ADL), and Short Form-36 (SF-36) at baseline and most recent follow-up. Magnetic resonance imaging was used to evaluate the cartilage repair morphologic characteristics in 14 cases.nnnRESULTSnTwenty-two patients met the study criteria with a mean follow-up of 28.7 months (range, 17.7-57.8 months). The mean patellar lesion size was 165.6 +/- 127.8 mm(2), and the mean size of the donor plug was 9.7 +/- 1.1 mm in diameter with 1.8 +/- 1.4 plugs/defect. The mean preoperative IKDC score was 47.2 +/- 14.0 and improved to 74.4 +/- 12.3 (P = .028). The mean preoperative ADL score was 60.1 +/- 16.9 and increased to 84.7 +/- 8.3 (P = .022). The mean SF-36 also demonstrated an improvement, from 64.0 +/- 14.8 at baseline to 79.4 +/- 15.4 (P = .059). Nine patients underwent concomitant distal realignment and demonstrated improvement between preoperative and postoperative outcomes scores, but these differences were not statistically significant. Magnetic resonance imaging appearance demonstrated that all plugs demonstrated good (67%-100%) cartilage fill, 64% with fissures < 2 mm at the articular cartilage interface, 71% with complete trabecular incorporation, and 71% with flush plug appearance.nnnCONCLUSIONnPatellar AOT is an effective treatment for focal patellar chondral lesions, with significant improvement in clinical follow-up. This study suggests that patients with patellar malalignment may represent a subset of patients who have a poor prognostic outlook compared with patients with normal alignment.

Staphylococcus aureus stimulates inducible nitric oxide synthase in articular cartilage.

OBJECTIVEnTo determine if Staphylococcus aureus stimulates the L-arginine-nitric oxide (NO) synthase pathway in articular cartilage.nnnMETHODSnA heat-killed and sonicated (denatured) S. aureus preparation was added to cultures of bovine articular cartilage. NO production was measured as accumulated nitrite in the culture medium and by the NO synthase-dependent conversion of 3H-L-arginine to 3H-L-citrulline in cartilage homogenates. Inducible NO synthase (iNOS) messenger RNA (mRNA) expression was analyzed by Northern blot. Proteoglycan synthesis was measured by 35SO4 incorporation into glycosaminoglycan.nnnRESULTSnNitrite accumulation and 3H-L-citrulline formation in cartilage were elevated by denatured S. aureus (compared with unstimulated control cartilage) and inhibited by the NO synthase inhibitor N(G)-monomethyl-L-arginine. Northern blot analysis revealed increased iNOS mRNA expression in bovine chondrocytes in response to denatured S. aureus stimulation. Denatured S. aureus suppressed the accumulation of 35SO4-labeled macromolecules representing newly synthesized proteoglycans in bovine articular cartilage. The suppressed proteoglycan synthesis was due to the presence of NO.nnnCONCLUSIONnThese findings support the hypothesis that a component of S. aureus can stimulate iNOS in articular cartilage, and that NO generated from this enzyme down-regulates cartilage matrix proteoglycan synthesis.

Decision Making in Cartilage Repair Procedures

The treatment of isolated articular cartilage lesions remains a difficult clinical problem. Cartilage has a poor intrinsic capacity for repair. Untreated lesions persist indefinitely and can predispose affected joints to pain and dysfunction. Fortunately, the treatment options for these lesions continue to evolve and expand. However, a validated approach to the treatment of such lesions remains elusive. Decision making in these circumstances is highly variable between practitioners. We describe an approach to the patient with a symptomatic articular cartilage lesion. Consideration of certain parameters, including lesion size, lesion location, patient demand, body mass index, limb alignment, and treatment history should be considered when selecting a surgical approach. In addition, surgeons should understand the physiology of the cartilage repair method employed and how this relates to the postoperative rehabilitation program. Cartilage repair strategies are classified into the following: enhancement intrinsic repair response, cell-based, scaffold-based, cell plus scaffold-based, and whole tissue transplantation. A treatment algorithm based on lesion size, patient demand, and treatment (primary vs secondary) is presented.

The 50 Most Cited Articles in Orthopedic Cartilage Surgery

Objective To determine the 50 most cited articles in orthopedic cartilage surgery and their characteristics. Design A systematic review of the Science Citation Index Expanded was performed for articles related to cartilage surgery published in the 66 journals under the category “Orthopedics.” The 50 most cited articles were determined, and the following characteristics were analyzed for each article: authors, journal and year of publication, number of citations, geographic origin, article type (basic science or clinical), article subtype by study design, and level of evidence. Citation density (total number of citations/years since publication) was also computed. Results The 50 most cited articles ranged from 989 to 172 citations, with citation density ranging from 71.5 to 4.1. The publication years spanned from 1968 to 2008, with the 2000s accounting for half (25) of the articles and the highest mean citation density (14.6). The 50 most cited articles were published in 11 journals. The majority of the articles (29) were clinical, with level IV representing the most common level of evidence (10). The remaining basic science articles were most commonly animal in vivo studies (14). Stronger level of evidence was correlated with overall number of citations (P = 0.044), citation density (P < 0.001), and year of publication (P = 0.003). Conclusions Articles with stronger levels of evidence are more highly cited, with an increasing trend as evidence-based practice has been emphasized. This article list provides clinicians, researchers, and trainees with a group of “citation classics” in orthopedic cartilage surgery.

Marrow Stimulation and Microfracture for the Repair of Articular Cartilage Lesions

Small full-thickness chondral injuries of the knee can be treated by marrow stimulation techniques. In the United States, the technique used most frequently to address posttraumatic femoral cartilage defects is microfracture arthroplasty. This chapter reviews the history, underlying theory, technique, and outcomes of microfracture and other marrow stimulation techniques.

Articular Cartilage Resurfacing Using Synthetic Resorbable Scaffolds

Cartilage repair is a challenging clinical problem because once adult cartilage sustains damage, whether traumatic or pathological, an irreversible, degenerative process can occur (1). The resulting defects may lead to osteoarthritis (2–4). Attempts to repair articular cartilage have included implantation of artificial matrices, growth factors, perichondrium, periosteum, and transplanted cells (5), but to date no reliable, reproducible approach has been identified. Furthermore, repair tissue frequently lacks the physical structure and mechanical properties necessary to ensure long-term efficacy (6). It is reasonable to hypothesize that the inferior mechanical properties of the repair tissue are partially caused by inadequate support during healing.

Can Biologic Augmentation Improve Clinical Outcomes Following Microfracture for Symptomatic Cartilage Defects of the Knee? A Systematic Review:

Objective To perform a systematic review of clinical outcomes following microfracture augmented with biological adjuvants (MFX+) compared with microfracture (MFX) alone. Design The MEDLINE, Scopus, and Cochrane databases were searched for clinical studies on MFX+ for chondral defects of the knee. Study characteristics and clinical outcome score data were collected. Subjective synthesis was performed using data from randomized controlled studies to determine effect size of MFX+ procedures performed with either injectable or scaffold-based augmentation compared with MFX alone. Results A total of 18 articles reporting on 625 patients (491 MFX+, 134 MFX) were identified. Six studies were level II evidence and 1 study was level I evidence. Mean patient age range was 26 to 51 years, and mean follow-up ranged from 2 to 5 years. All studies demonstrated significant improvement in reported clinical outcome scores at follow-up after MFX+ therapy, and 87% of patients reported satisfaction with treatment. The most commonly reported treatment complication was postoperative stiffness (3.9% of patients). Subjective synthesis on randomized controlled trials demonstrated that 2/2 injectable MFX+ interventions had significantly greater improvements in International Knee Documentation Committee Subjective Knee Form (IKDC; P = 0.004) and Knee injury and Osteoarthritis Outcome Score (KOOS; P = 0.012) scores compared with MFX alone, while 2/2 trials on scaffolding MFX+ adjuvants showed comparable postoperative improvements. Conclusions MFX+ biological adjuvants are safe supplements to marrow stimulation for treating cartilage defects in the adult knee. Early literature is heterogenous and extremely limited in quality. Individual trials report both equivalent and superior clinical outcomes compared with MFX alone, making definitive conclusions on the efficacy of MFX+ difficult without higher quality evidence.

Cartilage Surgery in Revision ACL Reconstruction

Articular cartilage lesions are commonly associated with anterior cruciate ligament (ACL) tears and are often encountered at the time of ACL revision surgery. Concomitant cartilage lesions can affect outcome after ACL revision and should be addressed at the same time. We discuss different repair strategies for cartilage injury and their implementation in the context of revision ACL reconstruction.

Neglected rotatory knee dislocation: A case report

UNLABELLEDnWe report here a unique case of a 3 year neglected rotatory tibiofemoral dislocation associated with a lateral patellar dislocation. The rotational deformity was gradually corrected using a Taylor spatial frame and the patella was realigned by tibial tubercle osteotomy and transfer. The patient also underwent multiple soft tissue releases and quadricepsplasty to improve knee flexion. At nine year follow-up, the patient has good knee range of motion, a congruent knee joint and a good functional result.nnnCLINICAL RELEVANCEnTaylor spatial frame combined with other orthopedic approaches can be a useful tool while dealing with neglected knee dislocations.