The Caucasian Nasal Septum: An In Vivo Computed Tomography Study.

BACKGROUND: The nasal septum is composed of cartilaginous and bony components and an understanding of each component volume is essential in both functional and cosmetic surgery. OBJECTIVES: We sought to radiographically measure septal dimensions on cross sectional computer tomography (CT) images, establishing average parameters for normal anatomy among a single, Caucasian population group. METHODS: One hundred and fifty consecutive sinus CT scan images were examined and 100 cases with appropriate sagittal views were included in the study. On each septum, the sagittal CT images were assessed and 14 points were identified and 23 lengths measured and tabulated. Trigonometric formulae were used to accurately calculate surface areas of 11 resulting triangles which constituted the components of the nasal septum. RESULTS: Measurements from 100 patients were included, with a mean age of 50.2 years, constituting 47 males and 53 females. Our surface area mapping established the following areas for both males and females respectively (mm2): quadrangular cartilage 1148 and 981; vomer 894 and 741; perpendicular plate of ethmoid bone 1244 and 1006; and total surface area 3287 and 2728. Our only statistically significant comparison in the series was found in the female series when age and reducing quadrilateral cartilage size were compared, highlighting reducing size with age (P = 0.04). CONCLUSIONS: The study presents the largest published data series representing nasal septal measurements on CT images in a living Caucasian population. Our data demonstrates that septal size remains constant after adolescence, throughout our age-varied series (18-79 years), except in the female population where the quadrilateral cartilage reduces in size with age.

Quantifying Changes in Nasal Tip Support.

IMPORTANCE: Imparting surgical change to the nasal tip remains one of the most challenging aspects of rhinoplasty. The surgeon must assess the tip preoperatively and execute the necessary maneuvers to impart the desired change. OBJECTIVE: To assess nasal tip resistance to compression in a cadaveric model before and after specific rhinoplasty maneuvers using a novel method. DESIGN, SETTING, AND MATERIALS: Open rhinoplasty maneuvers were performed at an academic tertiary care center on 6 fresh-thawed cadaver heads. Assessment of tip support was performed with a motorized, computer-controlled test stand equipped with a digital load cell. Tip support was assessed by compression to a depth of 2.5 mm from contact both preoperatively and after each surgical maneuver. All force data were recorded in pound-force and converted to newtons (N) following analysis. MAIN OUTCOMES AND MEASURES: Nasal tip support, measured as resistance to compression, before and after various rhinoplasty maneuvers. RESULTS: Following the elevation of the skin-soft-tissue envelope with septoplasty, resistance to compression (1.82 N) was not significantly different from the preoperative assessment (1.60 N for all specimens). Tip support following placement of a caudal extension graft was significantly different from all other conditions (3.16 N; P < .01), showing support increased by more than 66% from preoperative assessment. Placement of columellar strut (1.28 N) did not show significant increase in tip support. Tip support was decreased slightly after placement of intradomal sutures, which was significant (1.22 N; P < .01). CONCLUSIONS AND RELEVANCE: This study demonstrates the use of materials testing equipment to assess and quantify change in tip support after several rhinoplasty maneuvers. Minor supporting maneuvers that rely on healing and scar do not significantly alter tip support in a cadaveric model. Caudal extension graft is an important maneuver imparting significant effect on nasal tip support. LEVEL OF EVIDENCE: NA.

What are some tips and pearls for preserving and improving nasal function when performing a cosmetic rhinoplasty?

PURPOSE OF REVIEW: Understanding nasal form and function is critical in performing successful cosmetic rhinoplasty. Careful evaluation of the patient's nasal airway with identification of areas of existing or potential obstruction is important in avoiding potential pitfalls that may compromise nasal function following rhinoplasty. This article will review surgical techniques that can be utilized to preserve and improve nasal function during cosmetic rhinoplasty. RECENT FINDINGS: Recent literature on nasal functionality focuses on the management of the internal and external nasal valve as well as the nasal septum during rhinoplasty. SUMMARY: Successful cosmetic rhinoplasty requires a thorough preoperative analysis of both aesthetic and functional characteristics of the nose. Close attention should be paid to the internal and external nasal valves and nasal septum before and during surgery to preserve and improve nasal function following cosmetic rhinoplasty.

Impact of airflow communication between nasal cavities on nasal ventilation.

OBJECTIVE: To investigate the impact of airflow communication between bilateral nostril sides on nasal ventilation. In addition, we try to validate the efficacy of the Draf III procedure from the aerodynamics perspective. METHODS: One health model and two disease models were constructed. These included 2 patients with nasal septum perforation and 1 patient who received the Draf III procedure. With the computational fluid dynamics method, indices such as airflow velocity and wall shear stress in the nasal cavity were detected and compared among the 3 subjects. RESULTS: The main pathway for airflow in the nasal cavity is the common meatus. Little airflow exchange occurred in the patient who underwent the Draf III procedure, and the wall shear stress around the communication site was as low as in the adjacent areas. However, when airflow communication occurred in the lower part of the nasal cavity, the airflow velocity and wall shear stress were obviously altered, and the ventilation function of the nasal cavity was impaired. CONCLUSION: Airflow communication in the upper part of the nasal cavity has little impact on nasal ventilation. Nonetheless, airflow communication occurring in the lower part of the nasal cavity disturbs the overall airflow distribution and a repair procedure is necessary.

Shape fidelity of native and engineered human nasal septal cartilage.

OBJECTIVE: To test engineered and native septal cartilage for resistance to deformation and remodeling under sustained bending loads and to determine the effect of bending loads on the biochemical properties of constructs. STUDY DESIGN: Prospective, basic science. SETTING: Laboratory. SUBJECTS AND METHODS: Human septal chondrocytes from 6 donors were used to create 12-mm constructs. These were cultured for 10 weeks and subjected to bending for 6 days. Free-swelling controls and native tissue from 6 donors were used for comparison. Shape retention, photo documentation, live-dead staining, and biochemical properties were measured. RESULTS: Live-dead staining showed no difference in cell survival between loaded constructs and free-swelling controls. The immediate shape retention of the constructs was 39.0% versus 24.4% for native tissue (P = .13). After 2 and 24 hours of relaxation, the constructs possessed similar shape retention to native tissue (26.9% and 16.4%; P = .126; 21.7% and 14.4%; P = .153). There was no significant change in construct shape retention from immediately after release to 2 hours of relaxation (39.0% and 26.9%, respectively; P = .238). In addition, the retention did not change significantly between 2 and 24 hours of relaxation (26.9% and 21.7%; P = .48). There was no significant difference in biochemical properties between loaded constructs and controls. CONCLUSION: The shape retention properties of human septal neocartilage constructs are comparable to human native septal cartilage. In addition, mechanical loading of neocartilage constructs does not adversely affect cell viability or biochemical properties. This study demonstrates that neocartilage constructs possess adequate shape fidelity for use as septal cartilage graft material.

A prospective, randomized, single-blinded controlled trial on biodegradable synthetic polyurethane foam as a packing material after septoplasty.

BACKGROUND: We evaluated synthetic polyurethane foam (SPF; Polyganics BV, Groningen, The Netherlands) as a packing material used after septoplasty compared with Merocel (Medtronic Xomed Surgical Products, Jacksonville, FL) in the aspects of clinical efficacy and the subjective severity of symptoms. METHODS: A prospective, randomized, single-blinded controlled study was performed in 64 patients who had undergone septoplasty. The patients were randomized to receive Merocel or SPF after septoplasty. Assessments of clinical efficacy on bleeding and pain were done and subjective symptoms related to packing materials were evaluated using questionnaires quantified by the visual analog scale. RESULTS: There was no difference in repacking or additional packing due to postoperative bleeding, bleeding and/or septal hematoma on the removal of packing, and the mucosal condition after packing removal during postoperative period between the Merocel and SPF groups. Bleeding and pain during packing removal was significantly lower in patients with SPF packing. Also, in the SPF group, patient's general satisfaction and willingness to reuse the material were higher compared with the Merocel group. CONCLUSION: SPF is as suitable as Merocel to be used after septoplasty with beneficial effects on bleeding and pain at packing removal.

Assessment of biphasic calcium phosphate to repair nasal septum defects in sheep.

BACKGROUND: Saddle nose and septal perforations are among the most surgically challenging situations in nasal reconstruction. They require a significant volume of autologous graft and a complex surgical procedure. The aim of this study was to evaluate the biocompatibility of the biphasic calcium phosphate implant in the nasal septum and its ability to replace septal skeleton with unilateral or bilateral exposure. METHODS: Thirty sheep underwent anterior nasal septum perforation. Only 20 septa were repaired with the implant exposed to nasal content on bilateral (group 2) and unilateral (group 3) sides. After 45 days of spontaneous cicatrization, the surface of new airway mucosa covering implants and the amount of closure were evaluated macroscopically. Light microscopy, histomorphometry, immunohistochemistry, and transmission electron microscopy were performed to assess soft-tissue growth and differentiation. Statistical analysis was performed by means of the Mann-Whitney test. RESULTS: The mean rate of mucoperichondrial flap recovery of the implant was 66 percent in group 2 and 82 percent in group 3, and was significantly different from that of the control group (p < 10(-4)). The mean amount of closure was 32 and 64 percent, respectively (p < 10(-3)). The thickness of the perichondrium was greater than the control on both sides (p < 10(-4)). Vascularized soft tissues and bone formation invaded pores of implants. No pathologic inflammation was observed in submucosa. Moderately differentiated and well differentiated newly formed epithelium were the most frequent types observed, with good correlation between immunostaining and morphologic features. CONCLUSION: These data suggest a good biocompatibility of biphasic calcium phosphate and its ability to repair the nasal septum in sheep.

[Analysis of the character of self-adaptation of nasal structure in patients with nasal septum deviation].

OBJECTIVE: To analyze the different characters of nasal airflow-field between 10 patients with nasal septum deviation and 20 healthy Chinese people by the method of three-dimensional reconstruction of these people's nasal cavity and numerical simulation of the flow field in these nasal cavity models. The character of airflow-field was considered by analyzing the relationship between the structure and function of the human nose. METHODS: Based on the data obtained from the CT images, 10 patients with nasal septum deviation and 20 healthy Chinese people's nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models was simulated with finite element method. The different characters of nasal airflow-field was analysed between two groups of people. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity. The airflow for patients with nasal septum deviation mainly passed through the broad nasal cavity, especially in the middle part of meatus of nose. In the healthy people group, the airflow mainly passed through the main side of the nasal cavity, especially in the middle and inferior part of the meatus of nose. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. In the patients with nasal septum deviation, the pressure mainly dropped in the part of the nasal septum deviation, accounting approximately 71.36% of the total pressure drop. In the group of healthy people, the pressure dropped mainly in the limen nasi, accounting approximately 58.78% of the total pressure drop. The nasal airway resistance of the patients with nasal septum deviation was larger than that in the group of healthy people. CONCLUSIONS: The three-dimensional nasal airway can reflect the characters of the human nasal airway. It can be used to analyze the change of the aerodynamic in nasal cavity caused by the abnormal anatomy of the nose. This experiment can proof that human nose has the function of self-adaptation, it can build a foundation for the construction of the model of self-adaptation of the human nose.

Variações anatômicas do complexo ostiomeatal: achados tomográficos em 200 pacientes / Anatomical variants of the ostiomeatal complex: tomographic findings in 200 patients

OBJETIVO: O objetivo deste trabalho foi verificar a freqüência e os tipos de variações anatômicas do complexo ostiomeatal. MATERIAIS E MÉTODOS: Foram revisadas 200 tomografias computadorizadas de pacientes com suspeita clínica de sinusopatia. RESULTADOS: Observamos um ou mais tipos de variações anatômicas em 83,5 por cento dos pacientes, as mais freqüentes envolvendo o corneto médio (84 por cento) e o septo nasal (34 por cento). Outras variantes anatômicas comuns encontradas foram a presença de aeração do agger nasi e células etmoidais infra-orbitárias (células de Haller). CONCLUSÃO: As variações anatômicas do complexo ostiomeatal anterior são muito corriqueiras. As mais freqüentes envolvem o corneto médio e o septo nasal.

OBJECTIVE: The present study was aimed at evaluating the frequency and types of anatomical variants of the ostiomeatal complex. MATERIALS AND METHODS: Computed tomography studies of 200 patients evaluated for clinical suspicion of sinusopathy were reviewed. RESULTS: Two or more types of anatomical variants were observed in 83.5 percent of the patients. The most frequent anatomical variants involved the middle turbinate (84 percent) and the nasal septum (34 percent). Other common variants found were the presence of pneumatized agger nasi cells and infraorbital ethmoid cells (Haller cells). CONCLUSION: The prevalence of anatomical variants in the ostiomeatal complex is high, the most frequent ones involving the middle turbinate and the nasal septum.

Engineering of a straighter septum: numerical model of mechanical stress relaxation in laser-heated septal cartilage.

BACKGROUND AND OBJECTIVES: Successful application of laser cartilage reshaping (LCR) for the in-situ treatment of structural deformities in the nasal septum has generated increasing clinical interest, because septoplasty is among the top five most common operations performed. However, few studies have investigated stress fields existing in the nasal septal cartilage during LCR of septal deviations. The objectives of this study were to: (1) formulate a finite-element model describing stress fields in mechanically straightened septum, (2) calculate stress fields in the septum after a given pattern of laser irradiation produced thermally induced stress relaxation in selected sites, and (3) investigate the dependence of the overall stress relaxation in a straightened septum as a function of the number, location and size of laser irradiation sites. METHODS: The cartilagenous nasal septum was modeled as 24 x 24 x 1.5 mm slab. The deviation was represented as a bulge in the center of the septum with a maximum elevation above the surface of 2 mm. A straightening deformation was represented in form of displacement boundary condition applied to the bulge. Laser irradiation applied in a rectangular pattern of several spots was assumed. The effect of thermally induced stress relaxation was modeled as a simultaneous change in the cartilage mechanical properties and reduction of strain occurring within irradiated spots according to the heating history. The finite-element method was used to calculate stress fields within the straightened septum and the force of reaction to the straightening deformation before and after laser irradiation. RESULTS: Straightening deformation produced a highly non-homogeneous stress field with both regions of tension and compression present. Reaction force decreased with increasing number of irradiation sites and delivered laser energy. The model predicts that laser irradiation reducing reaction force by approximately 95% results in approximately 50% thermal damage to septal cartilage. CONCLUSIONS: A numerical model of stress fields in laser-reshaped deviated septum has been developed. The model shows highly non-homogeneous stress distributions before and after laser treatment. The model predicts that sufficiently high reduction of reaction force can be obtained with a localized laser treatment.

Surgery of the nasal septum.

Long-term results after septoplasty are not satisfactory. Apart from a recurrence of deviation, there are various reasons for this: false preoperative analysis, complete straightening of the septum, and a disturbed nasal cycle. Preoperative functional diagnostics with a combination of rhinoresistometry, acoustic rhinometry, and long-term rhinoflowmetry are necessary for differentiating between "physiological" and "pathological" septal deviations and recognizing other causes for obstruction. The surgical procedure of septoplasty includes approach, mobilization, resection, reposition, and finally reconstruction of all three layers. The goal of the operation should not be complete straightening of the nasal septum. The space between the septum and turbinates is of utmost importance. It should not be enlarged as much as possible; rather, it must be shaped in such a way as to allow freely congestion and decongestion reciprocal on the two sides during the nasal cycle.

Cartilage regeneration in the rabbit nasal septum.

OBJECTIVE: Rhinoplasty frequently includes harvesting of nasal septal cartilage. The objective of this prospective basic investigation is to determine whether cartilage can regenerate after submucosal resection (SMR) of the nasal septum in the rabbit. Neocartilage formation has not heretofore been described in this model. METHODS: By lateral rhinotomy, SMR was performed on 17 rabbits followed by reapproximation of the perichondrium. After 7 months, septi were fixed, sectioned, and examined histologically. Findings were photographed and data tabulated according to location and extent. RESULTS: Sites of matrix-secreting isogenous chondrocyte islands were identified between the perichondrial flaps of every animal, principally in the anterior inferior septum. The width of the islands averaged 190 microm, and the mean neocartilage height was found to be 840 microm. The newly formed cartilage consisted of chondrocytes within chondrons and was comparable in shape and structure to native septal cartilage. CONCLUSIONS: After SMR, rabbit cartilage tissue can regenerate and form matrix within the potential space created by surgery. The surrounding stem cell-rich perichondrium may be the site of origin for these chondrocytes. These findings suggest that after SMR of the human nasal septum, it may be possible for new cartilage tissue to develop provided the mucosa is well approximated. This biologic effect may be enhanced by insertion of cytokine-rich tissue scaffolds that exploit the native ability of septal perichondrium to regenerate and repair cartilage tissue.

Different swelling mechanisms in nasal septum (Kiesselbach area) and inferior turbinate responses to histamine: an optical rhinometric study.

OBJECTIVE: To determine whether the inferior turbinate, which contains swelling bodies, and the nasal septum (Kiesselbach area), characterized by a dense arterial mesh, exhibit different swelling mechanisms in allergic nasal reactions. DESIGN: Two optical rhinometers were used to examine 11 patients in the clinic. Optical rhinometry is based on the transillumination of the nasal septum and inferior turbinate or the whole nose with monochromatic light. The instrument's wavelength can be adjusted to the absorption characteristics of reduced hemoglobin, oxygen-saturated hemoglobin, and water. SETTING: Outpatient university otolaryngology clinic. PATIENTS: Eleven young, healthy, nonsmoking, nonpregnant subjects (6 men and 5 women), mean age, 32.4 years (age range, 27-37 years), with no history of exposure to toxic substances, allergies, or other significant diseases. INTERVENTIONS: Optic rhinometry evaluation during the course of nasal histamine administration. MAIN OUTCOME MEASURES: Light extinction at various wavelengths. RESULTS: Following administration of histamine, in the nasal septum, the wavelength of 950 nm (edema) showed the strongest increase of light extinction; in the inferior turbinate, it was the wavelength of 786 nm (oxygenated hemoglobin). In the whole nose, the wavelength of 880 nm (edema plus hemoglobin) exhibited the largest increase of extinction. CONCLUSIONS: Swelling of the nasal septum (Kiesselbach area) in nasal allergic reactions is caused mainly by edema, whereas swelling of the inferior turbinate is due mainly to an increase in volume of blood that is highly saturated with oxygen. Swelling of the whole nose is characterized by the combination of both, edema and increase in blood volume.

The regulation of expanded human nasal chondrocyte re-differentiation capacity by substrate composition and gas plasma surface modification.

Optimizing re-differentiation of clinically relevant cell sources on biomaterial substrates in serum containing (S+) and serum-free (SF) media is a key consideration in scaffold-based articular cartilage repair strategies. We investigated whether the adhesion and post-expansion re-differentiation of human chondrocytes could be regulated by controlled changes in substrate surface chemistry and composition in S+ and SF media following gas plasma (GP) treatment. Expanded human nasal chondrocytes were plated on gas plasma treated (GP+) or untreated (GP-) poly(ethylene glycol)-terephthalate-poly(butylene terephthalate) (PEGT/PBT) block co-polymer films with two compositions (low or high PEG content). Total cellularity, cell morphology and immunofluorescent staining of vitronectin (VN) and fibronectin (FN) integrin receptors were evaluated, while post-expansion chondrogenic phenotype was assessed by collagen types I and II mRNA expression. We observed a direct relationship between cellularity, cell morphology and re-differentiation potential. Substrates supporting high cell adhesion and a spread morphology (i.e. GP+ and low PEG content films), resulted in a significantly greater number of cells expressing alpha5beta1 FN to alpha(V)beta3 VN integrin receptors, concomitant with reduced collagen type II/ImRNA gene expression. Substrates supporting low cell adhesion and a spherical morphology (GP- and high PEG content films) promoted chondrocyte re-differentiation indicated by high collagen type II/I gene expression and a low percentage of alpha5beta1 FN integrin expressing cells. This study demonstrates that cell-substrate interactions via alpha5beta1 FN integrin mediated receptors negatively impacts expanded human nasal chondrocyte re-differentiation capacity. GP treatment promotes cell adhesion in S+ media but reverses the ability of low PEG content PEGT/PBT substrates to maintain chondrocyte phenotype. We suggest alternative cell immobilization techniques to GP are necessary for clinical application in articular cartilage repair.

Shape retention in porcine and rabbit nasal septal cartilage using saline bath immersion and Nd:YAG laser irradiation.

BACKGROUND AND OBJECTIVES: The process of altering the shape of cartilage using heat has been referred to as thermoforming, and presents certain clinical benefits in reconstructive surgical procedures within the head and neck. Thermoforming allows cartilage in the upper airway and face to be reshaped without the use of classic surgical maneuvers such as carving, morselizing, or suturing. The goal of this study was to determine the dependence of cartilage shape change on both temperature and laser dosimetry using two thermoforming methods: saline bath immersion and laser irradiation. STUDY DESIGN/MATERIALS AND METHODS: Ex-vivo rabbit and porcine nasal septal cartilages were mechanically deformed and reshaped using the two thermoforming methods. With saline bath immersion using rabbit cartilage, each specimen was deformed by securing it to a small copper tube (outer diameter 8 mm) using dental bands. For porcine cartilage immersed in a saline bath, each sample was mechanically deformed between two pieces of wire mesh attached to a semicircular acrylic block. With both porcine and rabbit cartilage, the specimen and apparatus were then immersed in a hot saline bath for time intervals varying from 20 and 320 seconds and at constant temperatures between 62 and 74 degrees C. In laser reshaping, the cartilage specimens were mechanically deformed on a jig and consecutively irradiated with an Nd:YAG laser (lambda = 1.32 microm) in several spots for 6-16 seconds and irradiances of 10.2-40.7 W/cm2 per spot. After either saline bath heating or irradiation, cartilage specimens were immersed in room temperature saline for 15 minutes, then upon removal from the jig the length between the ends of each specimen was measured in order to calculate the resulting bend angle. RESULTS: The transition zone for cartilage reshaping was defined as where a significant increase in bend angle was observed between consecutive times of immersion/irradiation at the same temperature/irradiance. For the saline bath experiments, the transition zone was observed between 59-68 degrees C and 62-68 degrees C for porcine and rabbit cartilage, respectively. Similar transition zones occurred with laser irradiation below irradiances of 20.4 W/cm2 for both porcine and rabbit cartilage. In addition, the dosimetry pairs in the transition zones produce peak temperatures below the thresholds determined from the saline bath immersion studies. CONCLUSIONS: The critical transition temperature region was determined by the sharp increase in bend angle at consecutive times of immersion at the same temperature. This range was determined to be 59-68 degrees C and 62-68 degrees C for porcine and rabbit cartilage, respectively. Similar transition zones for dosimetry occurred below 20.4 W/cm2 during cartilage irradiation in both species.

Identification of chondrocyte proliferation following laser irradiation, thermal injury, and mechanical trauma.

BACKGROUND AND OBJECTIVE: Cartilage has a limited regenerative capacity, and there are a lack of reliable techniques and methods to stimulate growth of new tissue to treat degenerative diseases and trauma. This study focused on identifying chondrocyte cell proliferation in ex vivo cartilage tissue following heating Nd:YAG laser using whole-mount analysis and flow cytometry, and compared findings with results produced by contact, and water bath heating methods, mechanical injury, and the addition of transforming growth factor-beta (TGF-beta). STUDY DESIGN/MATERIALS AND METHODS: Ex vivo rabbit nasal septal cartilages were either irradiated with an Nd:YAG laser (lambda = 1.32 microm, 2-16 seconds, 6 W/cm(2)), heated by immersion in a warm saline bath, heated by direct contact with a metal rod, or mechanically damaged by scoring with a scalpel or crushing. After treatment, specimens were incubated for 7 or 14 days in growth media containing 10 microM bromodeoxyuridine (BrdU). Additional specimens were cultured with both BrdU and TGF-beta. Both whole-mount BrdU-double-antibody detection techniques and flow cytometry were used to determine the presence of DNA replication as a marker of proliferation. RESULT: An annular region of regenerating chondrocytes was identified surrounding the laser irradiation zone in whole-mount tissue specimens, and the diameter of this region increased with irradiation time. Using whole-mount analysis, no evidence of chondrocyte DNA replication was observed in tissues heated using non-laser methods, grown in TGF-beta, or mechanically traumatized. In contrast, flow cytometry identified the presence of BrdU-positive cells in the S-phase of the cell cycle (synthesis of DNA) for all protocols, indicating chondrocyte proliferation. The percentage of cells that are in S-phase increased with irradiation time. CONCLUSION: These data provide evidence that laser irradiation, along with other thermal and mechanical treatments, causes a proliferative response in chondrocytes, and this is observed ex vivo in the absence of cellular and humoral repair mechanisms. The advantage of using optical methods to generate heat in cartilage is that microspot injuries could be created in tissue and scanned across surfaces in clinical applications.