Arthroscopic Probe Research Articles

Diagnostic Knee Arthroscopy and Partial Meniscectomy.

Knee arthroscopy is the most commonly performed orthopaedic procedure in the United States. Indications have grown exponentially since the procedure was first popularized by Watanabe and Jackson. Treatment of meniscal tears is the most common reason for knee arthroscopy, with approximately 700,000 arthroscopic partial meniscectomies performed annually. Other indications include assistance for cruciate ligament reconstruction, osteochondral lesions, removal of loose bodies, synovectomy, and septic arthritis. Arthroscopy is accomplished with the use of two small incisions on either side of the patella at the anterior aspect of the knee. An arthroscope is inserted through one incision and used to view the image on a monitor, while the second incision is employed for instrumentation. An examination with the patient under anesthesia should always be performed prior to the initiation of the procedure. The patient is positioned with the knee flexed and a lateral post secured to the side of the bed. Standard anteromedial and anterolateral portals are made, and an arthroscope is introduced through the anterolateral portal. Diagnostic arthroscopy is performed in a systematic fashion. Meniscal tears and other pathology are identified. With use of an arthroscopic probe, the features of the meniscal tear are determined. Arthroscopic punches and shavers are used to debride torn portions back to a stable rim. Knee arthroscopy is a highly effective procedure. Outcomes after partial medial meniscectomy are good to excellent in 80% to 100% of patients. A recent cost-effectiveness analysis demonstrated that knee arthroscopy is more cost-effective than coronary artery bypass surgery or total knee arthroplasty.

Shoulder Arthroscopy Does Not Adequately Visualize Pathology of the Long Head of Biceps Tendon.

Background:Pulling the long head of the biceps tendon into the joint at arthroscopy is a common method for evaluation of tendinopathic lesions. However, the rate of missed diagnoses when using this technique is reported to be as high as 30% to 50%.Hypothesis:Tendon excursion achieved using a standard arthroscopic probe does not allow adequate visualization of extra-articular sites of predilection of tendinopathy.Study Design:Descriptive laboratory study.Methods:Seven forequarter amputation cadaveric specimens were evaluated. The biceps tendon was tagged to mark the intra-articular length and the maximum excursions achieved using a probe and a grasper in both beach-chair and lateral positions. Statistical analyses were performed using analysis of variance to compare means.Results:The mean intra-articular and extra-articular lengths of the tendons were 23.9 and 82.3 mm, respectively. The length of tendon that could be visualized by pulling it into the joint with a probe through the anterior midglenoid portal was not significantly different when using either lateral decubitus (mean ± SD, 29.9 ± 3.89 mm; 95% CI, 25.7-34 mm) or beach-chair positions (32.7 ± 4.23 mm; 95% CI, 28.6-36.8 mm). The maximum length of the overall tendon visualized in any specimen using a standard technique was 37 mm. Although there was a trend to greater excursion using a grasper through the same portal, this was not statistically significant. However, using a grasper through the anterosuperior portal gave a significantly greater mean excursion than any other technique (46.7 ± 4.31 mm; 95% CI, 42.6-50.8 mm), but this still failed to allow evaluation of Denard zone C.Conclusion:Pulling the tendon into the joint with a probe via an anterior portal does not allow visualization of distal sites of predilection of pathology. Surgeons should be aware that this technique is inadequate and can result in missed diagnoses.Clinical Relevance:This study demonstrates that glenohumeral arthroscopy does not allow visualization of common areas of pathology of the long head of the biceps tendon.

Visualization of the Extra-Articular Portion of the Long Head of the Biceps Tendon During Intra-Articular Shoulder Arthroscopy

To quantify the amount of the extra-articular long head of the biceps tendon (LHBT) seen during intra-articular shoulder arthroscopy by pulling the tendon into the joint with a probe through an anterior portal while viewing through a standard posterior portal. Intra-articular shoulder arthroscopy was performed on 10 forequarter cadaveric specimens. The extra-articular portion of the LHBT was evaluated by pulling the tendon into the joint with an arthroscopic probe inserted through an anterior portal. The tendon was marked at the pulley insertion on the humerus with a vascular clip before and after the tendon was pulled into the joint. An open deltopectoral approach was performed, and the amount of extra-articular tendon visualized was calculated as an absolute amount and in relation to nearby anatomic structures. An additional 1.9 cm (range, 1.4 to 2.6 cm) of extra-articular LHBT was viewed by pulling the tendon into the joint with an arthroscopic probe through an anterior portal during shoulder arthroscopy. This represented 30.8% of the extra-articular portion of the tendon, 47.7% of tendon in the bicipital groove, and 76.3% of the tendon that lies under the area from the pulley insertion to the distal edge of the transverse humeral ligament. During intra-articular shoulder arthroscopy, the extra-articular portion of the LHBT is incompletely visualized by pulling the tendon into the joint with a probe placed through an anterior portal while viewing through a standard posterior portal. An additional extra-articular portion of the LHBT may be viewed by pulling the tendon into the joint with an arthroscopic probe during shoulder arthroscopy.

A Portable Arthroscopic Diagnostic Probe to Measure the Viscoelasticity of Articular Cartilage

Tissue engineering has been increasingly applied to treat diseases of the joints that adversely affect components such as cartilage and ligaments. These components do not contain blood vessels and nerves; the risk of rejection during tissue transplantation is therefore less than that for other organs. Treatment of cartilage and ligaments requires highly skilled surgeons, however, and it is necessary to establish a quantitative evaluation method. It is difficult to measure the mechanical properties of cartilage because of its viscoelasticity. Sensing technology that enables uniform qualitative evaluation is therefore desired. In this study, a portable diagnostic probe was developed and the viscoelasticity of cartilage was measured quantitatively over a short period of time. The probe was designed based on the Voigt model and comprises a piezoelectric actuator, a force sensor, and a contact probe. Stiffness and viscosity coefficients of various samples such as silicone rubber and the bovine meniscus were measured, and the accuracy of the developed probe was evaluated. Finally, the mechanical properties of human articular cartilage were measured using the diagnostic probe.

Effects of Arm Position on Maximizing Intra-Articular Visualization of the Biceps Tendon: A Cadaveric Study

The purpose of this study was to assess the intra-articular length of the biceps tendon in various shoulder and arm positions and identify the position in which the extra-articular portion of the tendon is maximally visualized within the glenohumeral joint. We measured 18 positions in 4 fresh-frozen cadaveric shoulders for a total of 72 measurements. In each measurement the position of the proximal biceps tendon was measured relative to a baseline measurement in neutral position (0° shoulder flexion, 0° shoulder abduction, 0° elbow flexion, 0° shoulder rotation). Positions measured ranged between the following: 0° and 30° shoulder flexion; 0° and 40° shoulder abduction; 0° and 90° elbow flexion; and 0° neutral, 30° internal, and 30° external shoulder rotation. The position creating the greatest increase in intra-articular biceps tendon length from baseline was 30° shoulder flexion, 40° shoulder abduction, 90° elbow flexion, and 0° rotation. On average, 56% of the tendon within the bicipital groove is brought into view by the maximal position relative to baseline. In maximizing intra-articular biceps tendon length, the effect of elbow flexion was highly significant (P < .001) and the combined effect of shoulder flexion-abduction was significant (P = .016). The position of 30° shoulder flexion, 40° shoulder abduction, and 90° elbow flexion significantly increases the excursion of the proximal biceps tendon relative to a neutral position. Over 50% of the tendon within the bicipital groove at baseline can be pulled out of the groove by placing the extremity in the maximal position and using an arthroscopic probe. Rotation of the humerus does not improve intra-articular excursion. Maximizing the intra-articular tendon length by arm positional change is likely to be useful for arthroscopic examination of the biceps tendon.

Small Medial Meniscocapsular Separations: A Potential Cause of Chronic Medial-Side Knee Pain

To describe clinical characteristics, surgical findings, and functional outcome after arthroscopic repair of a unique type of meniscocapsular separation. We retrospectively reviewed office charts, magnetic resonance imaging (MRI) scans, operative reports, and arthroscopic images of 6 patients who underwent surgery between January 2007 and May 2009, in whom a medial meniscocapsular separation measuring less than 5 mm in length was identified and treated. Inclusion criteria were medial-side knee pain unresponsive to nonoperative management, negative MRI findings, and an isolated meniscocapsular separation injury detected on arthroscopy and repaired with 1 stitch. Patients were contacted and completed questionnaires that included subjective International Knee Documentation Committee, Tegner, and Marx scores. Of the 6 patients, 5 were female patients aged 14 to 18 years who were involved in sports. All patients recalled an acute twisting knee injury. Symptoms were related mainly to sports and were absent or very minimal during activities of daily living. On physical examination, the medial joint line was tender in all patients, whereas medial-side knee discomfort while squatting (i.e., baseball catcher's position) and McMurray tests were positive only in some. The negative MRI scans used a 3-T magnet in 5 cases and a 1.5-T magnet in 1 case. The duration of symptoms from injury to surgery was between 6 months and 9 years in 5 cases. On arthroscopy, all patients had a medial meniscocapsular separation measuring less than 5 mm in length that was identified when the tip of the arthroscopic probe was inserted into the lesion. This was repaired with a single all-inside stitch. The mean latest follow-up was 31 months (range, 15 to 38 months). The mean subjective International Knee Documentation Committee score was 87 at latest follow-up. Tegner and Marx scores showed that after surgery, 5 patients regained their preinjury level of activity. Meniscocapsular separation can involve a segment of less than 5 mm in length, be occult on MRI, be challenging to visualize on arthroscopy, and lead to chronic medial-side knee pain. Critical evaluation with a history, physical examination, and careful arthroscopic inspection of the medial meniscus can lead to appropriate treatment with a good to excellent outcome after repair. Level IV, therapeutic case series.

The arthroscopic and ultrasonographic boundaries of the equine femorotibial joints

While descriptions of the visible soft tissues of the femorotibial joints exist for both arthroscopy and ultrasonography, there are few examples in the literature that discuss in detail the combined findings of these modalities. To further elucidate the ultrasonographic and arthroscopic boundaries of the normal equine femorotibial joints and improve the understanding of the benefits and limitations of each individual modality. Simultaneous arthroscopy and ultrasonography were performed in 10 equine cadaver stifles as well as bilateral stifles on a horse that underwent nonrecovery surgery. The arthroscopic probe was visualised ultrasonographically and concurrent video and still images acquired. Arthroscopy provided good visualisation of the cranial meniscal ligaments, the distal portion of the cranial cruciate ligament, proximal portion of the medial collateral ligament within the fibrous tissue of the joint capsule and a limited view of the abaxial border of meniscus. Ultrasonography allowed for almost complete visualisation of the menisci, collateral ligaments and cranial meniscal ligaments and a portion of the cranial cruciate ligament. By comparing the ultrasonographically and arthroscopically visible structures, this study allowed for a more complete understanding of the advantages and limitations of each modality. The ability of ultrasonography to resolve mild pathological changes should be further explored. When used together, these modalities can provide a more global image of the femorotibial joints.

Probing forces of menisci: what levels are safe for arthroscopic surgery

PurposeTo facilitate effective learning, feedback on performance during arthroscopic training is essential. Less attention has been paid to feedback on monitoring safe handling of delicate tissues such as meniscus. The goal is to measure in vitro probing forces of menisci and compare them with a theoretical maximum probing force (TMPF).MethodMenisci samples of ten cadavers were mounted on force platforms to measure probing forces up to 20 N in three directions. Nineteen subjects participated: six novices (experience <60 arthroscopies), ten intermediates (>60 arthroscopies), and three faculty (>250 a year). All had to perform three tasks on each meniscus sample with an arthroscopic probe: push three times on the superior meniscal surface, perform one continuous run on the superior meniscal surface, and push three times on the inferior meniscal surface. The absolute maximum probing force (AMPF) was determined for each condition. A multivariable linear regression analysis was performed to assess the influence of experience on the force magnitude (P < 0.05). AMPFs were compared to the TMPF (estimated to be 8.5 N).ResultsThe AMPF of the push task was on average 2.8 N (standard deviation (SD) of 0.8 N), of the continuous run task 2.5 N (SD 0.9 N), and of the pull task 3.9 N (SD 2.0 N). Significant difference was present between experts and novices (P < 0.05). The AMPFs are in the same order of magnitude as the TMPF.ConclusionThe results indicate the necessity of using a safety level for tissue manipulation when training arthroscopy and a value for is magnitude.

A New Arthroscopic Technique to Determine Anterior-Inferior Glenoid Bone Loss: Validation of the Secant Chord Theory in a Cadaveric Model

The accuracy of a previously described method using the glenoid bare spot (GBS) as a reference point was compared with a new method using the secant chord theory (SCT), which relies on the circular geometry of the inferior glenoid to calculate bone loss. In 7 embalmed cadaveric shoulders a digital image of the glenoid face was used to calculate the area of the best-fit circle of the inferior glenoid. Osteotomy templates from the 3-o'clock to 6-o'clock position were created to make a simulated anterior-inferior bone defect of 12.5% and 25% of the area of the circle. Measurements were taken with an arthroscopic probe from 2 simulated posterior portal positions (9 and 10 o'clock) by use of 2 techniques-SCT and GBS-in the intact, 12.5% loss, and 25% loss states. In the intact state, measurements showed a mean SCT loss of 4.1% and GBS loss of 4.4%. In the 12.5% loss state, mean percent bone loss with GBS was 23.1% compared with 14.8% with SCT (P = .0001) at the 10-o'clock portal and 22.2% compared with 15.9% (P = .006) at the 9-o'clock portal. In the 25% loss state, mean percent bone loss with GBS was 31.5% compared with 26.6% with SCT (P = .002) at the 10-o'clock portal and 30.4% compared with 28.9% (P = .48) at the 9-o'clock portal. The SCT is shown to be a more accurate method of determining glenoid bone loss in an arthroscopic model; however, additional mathematic calculations are necessary. As shown in the intact state, there is an inherent small error of approximately 4% when arthroscopically determining bone loss. The technique may aid the clinician in quantifying glenoid bone loss and help determine when bone augmentation may be advisable.

Confocal Arthroscopic Assessment of Osteoarthritis In Situ

This study aimed to assess the ability of the laser scanning confocal arthroscope (LSCA) to evaluate cartilage microstructure, particularly in differentiating stages of human osteoarthritis (OA) as classified by the International Cartilage Repair Society (ICRS) OA grade definitions. Ten tibial plateaus from total knee arthroplasty patients were obtained at the time of surgery. Cartilage areas were visually graded based on the ICRS classification, imaged by use of a 7-mm-diameter LSCA (488-nm excitation with 0.5% [wt/vol] fluorescein, 20-minute staining period), and then removed with underlying bone for histologic examination with H&E staining. The 2 imaging techniques were then compared for each ICRS grade to ascertain similarity between the methods and thus gauge the techniques' diagnostic resolution. Cartilage surface degeneration was readily imaged and OA severity accurately gauged by the LSCA and confirmed by histology. LSCA and histologic images of specimens in the late stages of OA were seen to be mutually related even though they were imaged in planes that were orthogonal to each other. Useful and comparable diagnostic resolution was obtained in all imaged specimens from subjects with various stages of OA. This study showed the LSCA's ability to image detailed cartilage surface morphologic features that identify grade 1 through 4 of the ICRS OA grading system. The LSCA's imaging potential was best shown by its ability to resolve the fine collagen network present under the lamina splendens. The incorporation of high-magnification confocal technology within the confines of an arthroscopic probe has proved to provide the imaging requirements necessary to perform detailed cartilage condition assessment. In comparison to video arthroscopy, LSCA provides increased magnification along with improved contrast and resolution.

Haptic Feedback Can Provide an Objective Assessment of Arthroscopic Skills

The outcome of arthroscopic procedures is related to the surgeon's skills in arthroscopy. Currently, evaluation of such skills relies on direct observation by a surgeon trainer. This type of assessment, by its nature, is subjective and time-consuming. The aim of our study was to identify whether haptic information generated from arthroscopic tools could distinguish between skilled and less skilled surgeons. A standard arthroscopic probe was fitted with a force/torque sensor. The probe was used by five surgeons with different levels of experience in knee arthroscopy performing 11 different tasks in 10 standard knee arthroscopies. The force/torque data from the hand and tool interface were recorded and synchronized with a video recording of the procedure. The torque magnitude and patterns generated were analyzed and compared. A computerized system was used to analyze the force/torque signature based on general principles for quality of performance using such measures as economy in movement, time efficiency, and consistency in performance. The results showed a considerable correlation between three haptic parameters and the surgeon's experience, which could be used in an automated objective assessment system for arthroscopic surgery. Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic evaluation of cartilage degeneration using indentation testing—Influence of indenter geometry

It has been suggested that the early onset of cartilage degeneration might be detected with a handheld indentation probe during knee arthroscopy, prior to any visible change on the articular surface. Collagen degradation has been considered as the first sign of cartilage degeneration. Therefore, it is important to consider the collagen network as a distinct constituent in the study of arthroscopic evaluation of cartilage degeneration. The tip of an arthroscopic probe (indenter) was modeled as rigid and in contact with a cartilage/bone disk of sufficiently large radius to simulate an indentation in a joint. A fibril-reinforced model of cartilage, including streaming potentials and distinct constitutive laws for the proteoglycan matrix and collagen network, was used to determine the contact mechanics of indenter and cartilage. The finite element package ABAQUS was employed to obtain numerical solutions. A spherical indenter produces a relatively uniform deformation in cartilage, but can easily slide on the articular surface. In contrast, a cylindrical indenter produces great deformation gradients for quick compression rates, but does not slide as easily on the articular surface as the spherical indenter. Small porous and large solid indenters should be used to evaluate the properties of the proteoglycan matrix and collagen network, respectively, in order to minimize or maximize the fluid pressure in the corresponding case. When the collagen network is substantially degraded, the gradients of fluid pressure and deformation are greatly reduced regardless of indenter geometry. The indenter geometry including its porosity is important to the material safety of articular cartilage in indentation and precise evaluation of cartilage degeneration.

Electromechanical response of articular cartilage in indentation—considerations on the determination of cartilage properties during arthroscopy

A finite element formulation of streaming potentials in articular cartilage was incorporated into a fibril-reinforced model using the commercial software ABAQUS. This model was subsequently used to simulate interactions between an arthroscopic probe and articular cartilage in a knee joint. Fibril reinforcement was found to account for large fluid pressure at considerable strain rates, as has been observed in unconfined compression. Furthermore, specific electromechanical responses were associated with specific changes in tissue properties that occur with cartilage degeneration. For example, the strong strain-rate dependence of the load response was only observed when the collagen network was intact. Therefore, it is possible to use data measured during arthroscopy to evaluate the degree of cartilage degeneration and the source causing changed properties. However, practical problems, such as the difficulty of controlling the speed of the handheld probe, may greatly reduce the reliability of such evaluations. The fibril-reinforced electromechanical model revealed that high-speed transient responses were associated with the collagen network, and equilibrium response was primarily determined by proteoglycan matrix. The results presented here may be useful in the application of arthroscopic tools for evaluating cartilage degeneration, for the proper interpretation of data, and for the optimization of data collection during arthroscopy.

Improvement of arthroscopic cartilage stiffness probe using amorphous diamond coating

During arthroscopic evaluation of articular cartilage unstable contact and even slipping of the measurement instrument on the tissue surface may degrade the reproducibility of the measurement. The main aim of the present study was to achieve more stable contact by controlling the friction between articular cartilage surface and the arthroscopic cartilage stiffness probe (Artscan 200, Artscan Oy, Helsinki, Finland) using amorphous diamond (AD) coating. In order to obtain surfaces with different average roughnesses (R(a)), polished stainless steel disks were coated with AD by using the filtered pulsed arc-discharge (FPAD) method. Dynamic coefficient of friction (mu) between the articular cartilage (n = 8) and the coated plates along one non-coated plate was then determined. The friction between AD and cartilage could be controlled over a wide range (mu = 0.027-0.728, p < 0.05, Wilcoxon test) by altering the roughness. Possible deterioration of cartilage was investigated by measuring surface roughness after friction tests and comparing it with the roughness of the adjacent, untested samples (n = 8). Importantly, even testing with the roughest AD (R(a) = 1250 nm) did not damage articular surface. On the basis of the friction measurements, a proper AD coating was selected for the stiffness probe. The performance of coated and non-coated probe was compared by measuring bovine osteochondral samples (n = 22) with both instruments. The reproducibility of the stiffness measurements was significantly better with the AD-coated probe (CV% = 4.7) than with the uncoated probe (CV% = 8.2). To conclude, AD coating can be used to safely control dynamic friction with articular surface. Sufficient friction between articular surface and reference plate of the arthroscopic probe improves significantly reproducibility of the stiffness measurements.

Radiofrequency (electrosurgical) ablation of articular cartilage: a study in sheep

The objective of this study was to examine the effect of a bipolar ablation probe on experimentally roughened articular cartilage and compare it with the traditional mechanical shaving technique using the knee joint of sheep. Twenty-eight skeletally mature ewes were divided randomly into two groups: one group was treated with a rotating shaving device and another group was treated using the bipolar ablation probe (Bipolar Arthroscopic Probe; Electroscope, Inc, Boulder, CO). Animals were killed at 0, 6, 12, and 24 weeks, and histological sections of the experimental limbs were compared with sections of the opposite limb using a modified Mankin scale. The following variables were used to determine scores: surface (0-6), cells (0-4), hypocellularity (0-3), matrix staining (transitional zone [0-4], radiate zone [0-4], and focal empty lacunae or hypereosinophilic cells (0-3). Differences in scores for all response variables were calculated as treated limb minus sham limb. Response variables were formed: score >0 recoded as 1 (favorable response treated better than sham), score of 0 recoded as 2 (neutral response no differences), and score <0 recoded as 3 (unfavorable response treated worse than sham). Bipolar ablative probe-treated limbs had 14.29% favorable responses and 35.71% favorable or neutral responses, whereas shave-treated limbs had 0% favorable and only 7.14% favorable or neutral responses. For all variables, bipolar ablative probe-treated limbs had more favorable responses. The less severe histological change in the bipolar ablative probe-treated joints compared with the shave-treated joints suggests that bipolar ablation of articular cartilage may be a better treatment for chondromalacia than the usual shaving methods of debridement. Further, there were no pathological changes in the subchondral bone. Arthroscopy 1998 Sep;14(6):585-91

Evaluation of cartilage lesions on the medial femoral condyle as a cause of lameness in horses: 11 cases (1988-1994)

Objective— To evaluate clinical findings and response to treatment in horses in which cartilage lesions on the medial femoral condyle were a cause of lameness. Design— Retrospective case series. Sample Population— Medical records of 11 horses that had cartilage lesions on the medial femoral condyle detected during arthroscopy of the stifle. Procedure— Signalment, history, lameness examination, response to intra-articular anesthesia, radiographs of the stifle, observations during diagnostic arthroscopy, and treatment were extracted from the medical record of each horse. Follow-up examinations and outcome were available for all horses. Results— All horses in the study had lameness, but their gait improved after intra-articular injection of anesthetic. Abnormalities were not observed on radiography of the stifle. Diagnostic arthroscopy was performed on 12 affected joints in 11 horses. Cartilage was dimpled, wrinkled, and infolded, and a blunt arthroscopic probe could be inserted into the subchondral bone. In addition to focal lesions, 4 horses had generalized damage to cartilage on the medial femoral condyle. Focal cartilage lesions on the femoral condyle were debrided. In 2 horses. debridement was not performed because of extensive generalized damage to the cartilage. Six of 7 horses with focal cartilage lesions treated by debridement recovered completely and resumed previous activities. Clinical Implications— Cartilage lesions on the medial femoral condyle can cause lameness in performance horses. Diagnostic arthroscopy is necessary to make an accurate diagnosis. Debridement of focal cartilage lesions may allow some horses to successfully resume performance activities. (J Am Vet Med Assoc 1997;210:1649–1652)

顎関節に対する微細径ファイバースコープの応用 診断鏡の開発

To overcome the operational diffficulty of TMJ arthroscopy, and to reduce injury during the examination a fine needle fiber arthroscope was developed and clinically applied. The equipment is composed of a fine needle arthroscopic probe and a television monitor system with an output for a videorecorder and camera. The characteristics of this optical system are as follows:1) The fine needle arthroscope (0.8mm in diameter, 20 G) can be inserted into the narrow or tiny TMJ spaces, such as the lower joint compartment and also reduced iatrgenic injury to the joint tissues.2) There is no distortion of the picture or breakage of the scope by bending. The picture is clear enough for diagnostic purpose.3) Using this system it is possible to examine the joint both arthrographically, arthroscopically and to treat TMJ diseases, by means of pumping manipulation technique and injection of appropriate medicines. All of these manipulations are possible using only one insertion of the cannule (18 G) for each articular cavity under local anesthesia. 17 patients (19 TMJ) were examined by this system, and the results obtained are as follows:1) Adhesions were generally seen below the articular tubercle, and they were mostly white membrane like fibrous adhesion without blood vessel, similar lesions with debris were also seen in the lower articular cavity. It was possible to perform arthroscopic detachment by using this approach.2) Two types of disk perforation were observed, one without tissue reaction, the other with fibrous adhesion and granulation tissue.As mentioned above, very favorable results were obtained without any complications.