Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part III-indications for different clinical scenarios using the RAND/UCLA appropriateness method.

PURPOSE: The aim of the ESSKA 2022 consensus Part III was to develop patient-focused, contemporary, evidence-based, guidelines on the indications for revision anterior cruciate ligament surgery (ACLRev). METHODS: The RAND/UCLA Appropriateness Method (RAM) was used to provide recommendations on the appropriateness of surgical treatment versus conservative treatment in different clinical scenarios based on current scientific evidence in conjunction with expert opinion. A core panel defined the clinical scenarios with a moderator and then guided a panel of 17 voting experts through the RAM tasks. Through a two-step voting process, the panel established a consensus as to the appropriateness of ACLRev for each scenario based on a nine-point Likert scale (in which a score in the range 1-3 was considered 'inappropriate', 4-6 'uncertain', and 7-9 'appropriate'). RESULTS: The criteria used to define the scenarios were: age (18-35 years vs 36-50 years vs 51-60 years), sports activity and expectation (Tegner 0-3 vs 4-6 vs 7-10), instability symptoms (yes vs no), meniscus status (functional vs repairable vs non-functional meniscus), and osteoarthritis (OA) (Kellgren-Lawrence [KL] grade 0-I-II vs grade III). Based on these variables, a set of 108 clinical scenarios was developed. ACLRev was considered appropriate in 58%, inappropriate in 12% (meaning conservative treatment is indicated), and uncertain in 30%. Experts considered ACLRev appropriate for patients with instability symptoms, aged ≤ 50 years, regardless of sports activity level, meniscus status, and OA grade. Results were much more controversial in patients without instability symptoms, while higher inappropriateness was related to scenarios with older age (51-60 years), low sporting expectation, non-functional meniscus, and knee OA (KL III). CONCLUSION: This expert consensus establishes guidelines as to the appropriateness of ACLRev based on defined criteria and provides a useful reference for clinical practice in determining treatment indications. LEVEL OF EVIDENCE: II.

Effect of skill-based training vs. small-sided games on physical performance improvement in young soccer players.

Recently, there has been increasing attention to research related to the effect of skill-based or game-based training on soccer players' physical performance. Therefore, this study aimed to compare the effectiveness of skill-based training (SBT) at maximum intensity versus the small-sided game (SSG) on the physical performance characteristics of young soccer players during the pre-season period. Twenty-two male soccer players (mean age 15.3 ± 3 years) were randomly assigned to either an SBT or SSG fully controlled intervention programme, running parallel for eight weeks and held twice a week. On three non-consecutive days before and after training players completed a test battery consisting of the 20 m sprint, T-run, countermovement jump, running anaerobic sprint test (RAST) and 20 m shuttle run. Data were analysed with a two-way ANOVA test for repeated measures. SBT and SSG interventions induced a significant improvement in the anaerobic power (10.9% vs 6.2%), explosive power (8.5% vs 5.6%), VO2max (6.7% vs 6.5%) and vertical jump (5.3% vs 2.9%), respectively. When the improvements in the physical performance variables of both groups are compared, the SBT group achieved greater improvement than the SSG group in anaerobic power (by 4.7%), in explosive power (by 2.8%), in vertical jumping (by 2.3%), in the 20 m sprint (by 2.2%) and T-test scores (by 1.7%). However, improvements in the VO2max were similar in both groups. The results of the present study suggest that SBT at maximum intensity may be more effective than SSG in improving the physical performance characteristics of young soccer players in the pre-competitive season.

Editorial Commentary: Seasoning the Tissue to the Surgeon's Liking: Biologic Augmentation of Anterior Cruciate Ligament Reconstruction With Platelet-Rich Plasma and a Gelatin Sponge.

Augmentation of anterior cruciate ligament reconstruction with platelet-rich plasma and a gelatin sponge improves tendon to bone healing in a small animal model. A sponge may prolong platelet-rich plasma bioactivity time.

Editorial Commentary: Unraveling Gordian's Knot: Opioids in Arthroscopy Pain Management.

Pain management is crucial for a successful result after various knee surgeries. Opioids may be included in the postoperative pain management protocol but may be abused if not controlled. Following knee arthroscopy and related surgery, adolescent and young adult patients are commonly overprescribed opioids. The driving force behind opioid prescription should be explored in addition to reviewing and emphasizing perioperative interventions that can reduce postoperative opioid consumption, including wound injections and peripheral nerve blocks.

Effect of adjuvant hyperbaric oxygen on healing of cartilage lesions treated with microfracture: an experimental study in rats.

PURPOSE: The purpose of this experimental study was to investigate the effect of hyperbaric oxygen (HBO2) therapy combined with microfracture technique in the treatment of cartilage lesions. METHODS: Adult Wistar rats (n=44) were divided into six groups. In Groups A, B, C and D, ICRS* (* International Cartilage Repair Society) grade 4 cartilage lesions were made on the femoral sulcus of both knees. Lesions were microfractured on the left knees; the right knees had no further procedure. Groups E and F had no surgery. Groups A, C and E received HBO2 therapy once a day, six days a week postoperatively. Groups B, D and F had no HBO2 therapy. The animals in Groups A, B, E and F were sacrificed after two weeks; Groups C and D were sacrificed after four weeks. Semiquantitative scale - including filling of defect (microfracture hole), reparative tissue thickness, cell morphology and subchondral bone maturation - was used for evaluation. The Mann-Whitney test was used to compare individual and total scores. RESULTS: Total scores of the two-week group with adjuvant HBO2 therapy were significantly higher (P=0.0007) than the two-week standard treatment group. Except for subchondral bone maturation, individual scores were significantly higher in the two-week group with adjuvant HBO2 therapy. Total scores of the four-week groups were similar. Among individual scores of the four-week groups, filling of the defect (microfracture hole), and subchondral bone maturation were significantly higher (P=0.01, P=0.03) in groups with adjuvant HBO2 therapy. CONCLUSIONS: Adjuvant HBO2 therapy accelerates the healing process of cartilage lesions treated with microfracture in rats.

Are pelvic anatomical structures in danger during arthroscopic acetabular labral repair? Definition of safe bone depth.

PURPOSE: The purpose of this study was to evaluate safe depth for suture anchor insertion during acetabular labral repair and to determine the neighbouring structures at risk during drilling and anchor insertion. METHODS: Ten human cadaveric hips (six males and four females) were obtained. Acetabular labral surface was prepared and marked for right hips as 12, 1 and 3 o'clock positions, for left hips 12, 11 and 9 o'clock positions. Those were defined as anterior, anterior-superior and superior zones, respectively. These labral positions were drilled at defined zones. After measurements, depth of the bone at 10° and 20° drill angles on zones was compared statistically. RESULTS: Acetabular bone widths at investigated labral insertion points did not statistically differ. A total of 14 injuries in 60 penetrations occurred (23.3 %) with free drill penetrations, and no injuries occurred with stopped drill penetrations. The bone depth was gradually decreasing from 10° to 20° drill angles and from anterior to superior inserting zones without significant importance. The risk of perforation to the pelvic cavity started with 20 mm drill depth, and the mean depth for all insertions was calculated as 31.7 mm (SD 2.6). CONCLUSIONS: It is anatomically possible that some pelvic structures sustain iatrogenic injury during acetabular drilling for anchor placement. Being aware of mean pelvic vault is important in which drilling after excessive pincer rim trimming could easily decrease the depth of acetabular bone without a standard. Careful drilling by using stopped drill bit is crucial to prevent iatrogenic injury.

Drilling through lateral transmuscular portal lowers the risk of suprascapular nerve injury during arthroscopic SLAP repair.

PURPOSE: The aim of our study was to evaluate the risk of medial glenoid perforation and possible injury to suprascapular nerve during arthroscopic SLAP repair using lateral transmuscular portal. METHODS: Ten cadaveric shoulder girdles were isolated and drilled at superior glenoid rim from both anterior-superior portal (1 o'clock) and lateral transmuscular portal (12 o'clock) for SLAP repairs. Drill hole depth was determined by the manufacturer's drill stop (20 mm), and any subsequent drill perforations through the medial bony surface of the glenoid were directly confirmed by dissection. The bone tunnel depth and subsequent distance to the suprascapular nerve, scapular height and width, were compared for investigated locations. RESULTS: Four perforations out of ten (40 %) occurred through anterior-superior portal with one associated nerve injury. One perforation out of ten (10 %) occurred through lateral transmuscular portal without any nerve injury. The mean depth was calculated as 17.6 mm (SD 3) for anterior-superior portal and 26.5 mm (SD 3.6) for lateral transmuscular portal (P < 0.001). CONCLUSIONS: It is anatomically possible that suprascapular nerve could sustain iatrogenic injury during labral anchor placement during SLAP repair. However, lateral transmuscular portal at 12 o'clock drill entry location has lower risk of suprascapular nerve injury compared with anterior-superior portal at 1 o'clock drill entry location.

Palmaris longus tendon graft versus modified Weaver-Dunn procedure via dynamic button system for acromioclavicular joint reconstruction in chronic cases.

BACKGROUND: The hypothesis of this clinical study was that coracoclavicular (CC) reconstruction using autogenic palmaris longus graft through the GraftRope (PLG) system (Arthrex, Inc., Naples, FL, USA) would provide superior clinical and radiologic results compared with modified Weaver-Dunn procedure with the dynamic TightRope (Arthrex, Inc.) system (WDT). METHODS: Between 2008 and 2013, 32 patients (average age, 39.7 years; range, 22-60 years) underwent surgical reconstruction of chronic acromioclavicular (AC) joint dislocation. A modified WDT procedure was performed in 16 patients and autogenous PLG was performed in the other 16 patients. Patient data were collected retrospectively, with a final follow-up of 44.9 months (range, 29-60 months). The degree of AC joint displacement was evaluated by measuring the CC distance on the anteroposterior and axillary view. Clinical and functional outcomes were compared by American Shoulder and Elbow Surgeons and the Constant scores at final follow-up. RESULTS: Comparison between the WDT and PLG groups showed a significantly better outcome in the American Shoulder and Elbow Surgeons and the Constant scores (P < .01), in favor of the PLG group. Both groups showed an increased CC distance compared with the uninjured side, with a mean difference of 1.1 mm for the PLG and 3.3 mm for the WDT groups. A tolerable loss of reduction within the follow-up time was observed. Reduction loss was higher with the WDT group (P < .05). CONCLUSION: CC palmaris longus tendon graft reconstruction with GraftRope system was associated with functional and radiologic benefits. The palmaris longus graft with GraftRope system could be used in chronic cases.

Foreseeing the danger in the beach chair position: Are standard measurement methods reliable?

PURPOSE: The aim of this study is to show whether peripheral perfusion monitoring methods reflect central perfusion during shoulder arthroscopy at beach chair position. We hypothesized that mean arterial pressure (MAP), central heart rate (CHR) and peripheral oxygenation (SaO2) measurements individually will not parallel cerebral oximetry measurements by near-infrared spectroscopy (NIRS). METHODS: Between 2011 and 2012, 53 patients who had arthroscopic rotator cuff repair surgery in the beach chair position were enrolled prospectively. Median ages of the patients were 58 (range 42-68) years. The regional cerebral oxygen saturation value of each hemisphere was continuously monitored by the use of NIRS. MAP, CHR, SaO2 and both hemispheric cerebral oxygen saturation values were recorded at six time periods peri-operatively. Correlation and differences between parameters were evaluated. RESULTS: Cerebral oxygen saturation of right hemisphere was dropped >20 % in 28.3 and 45.3 % of the patients. At left hemisphere, cerebral oxygen saturation was dropped >20 % in 20.8 and 43.4 % of the patients. Peripheral saturation values were statistically different from cerebral saturation values (p < 0.001). On the other hand, there was a correlation between cerebral saturation and MAP values (p < 0.05). CONCLUSION: Cerebral oximetry by NIRS may prove useful as a monitor for cerebral ischaemia. In the absence of NIRS, CHR can partially detect abnormalities but not trustable, and MAP is the most reliable method for monitoring.

The effect of environmental pH change on bovine articular cartilage metabolism: implications for the use of buffered solution during arthroscopy?

PURPOSE: The purpose of this study is to determine the immediate effects of pH change on the metabolism of bovine chondrocytes. METHODS: Bovine osteochondral explants were pre-cultured and placed in Ringer's lactate solution. Thirty explants were randomly divided into 3 groups. Buffered Ringer's lactate, pH 7.2, was used in Group I; buffered Ringer's lactate, pH 7.4 (normal bovine knee joint pH), was used in Group II; and this group was also set as the control group. Buffered Ringer's lactate, pH 7.6, was used in Group III. All specimens were soaked for 2 h. RNA yield analyses were performed to evaluate the changes in cartilage metabolism at different pH levels. RESULTS: Mean RNA yields of (hypoxia-induced factor) 1α that were immersed at pH 7.2 and 7.6 were 10.5- and 9.9-fold from base, respectively, which were lower compared to explants at pH 7.4 which was found as 15.2-fold. Mean RNA yields of aggrecan that were immersed at pH 7.2 and 7.6 were 12.2- and 13.6-fold from base, respectively, which were lower compared to explants at pH 7.4 which was found as 20-fold. RNA yields of collagen type II at pH 7.2 and 7.6 were 16.1- and 16.6-fold from base, respectively, which were lower compared to explants immersed at pH 7.4 which was found as 22.1-fold. CONCLUSION: The findings of the presented study suggest that short-term exposures to both acidic and basic pH may have effects on chondrocyte function. Our findings also indicate that exposures to solutions with a pH different from normal by only 0.2 unit could suppress chondrocyte metabolism and RNA synthesis. CLINICAL RELEVANCE: Using buffered irrigation solutions with a pH closer to the normal joint pH could be more physiologic and causes less ultra-structural damage than regular irrigation solutions. LEVEL OF EVIDENCE: II.

Comparison of Side-to-Side Difference in Posterior Tibial Slope in Knees With Acute Versus Chronic Anterior Cruciate Ligament Deficiency.

Background: The posterior tibial slope (PTS) is an important feature in knee joint biomechanics and indicates anterior-posterior knee stability. Increased PTS is a known risk factor for both primary anterior cruciate ligament (ACL) rupture and postreconstruction rerupture. Purpose: To investigate the effect of long-term exposure to ACL deficiency on the PTS and the sagittal anatomy of the proximal tibia. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 44 patients (38 men, 6 women) with a history of knee injury and ACL rupture confirmed by magnetic resonance imaging and physical examination were included in this study. Patients were divided into those with chronic ACL deficiency (group 1: injured ≥5 years prior; n = 22) and acute ACL deficiency (group 2: injured <1 year prior; n = 22). The medial and lateral tibial plateau PTS and anterior tibial translation were measured on monopodal weightbearing knee radiographs at 20° of flexion. The mechanical tibiofemoral angle (MTFA) and the medial proximal tibial angle (MPTA) were measured using an orthoroentgenogram. The side-to-side difference between the affected and unaffected knees was also calculated for all measurements. Results: The mean duration of exposure to ACL deficiency was 7.6 years (range, 5-15 years) in group 1 and 4.4 months (range, 1-11 months) in group 2. Regarding the side-to-side differences in angular measurements, a higher medial PTS (affected vs unaffected: 12.4° vs 10.1°; P = .007), higher lateral PTS (11° vs 8.9°; P = .011), and increased varus alignment on both the MTFA (4.3° vs 2.4°; P = .036) and the MPTA (84.9° vs 86.3°; P = .033) were found in group 1, while no significant differences in angular measurements were found in group 2. Compared with group 2, patients in group 1 had a significantly higher side-to-side difference in the medial PTS (2.3° vs 0.1°; P = .0001), lateral PTS (2.1° vs 0.4°; P = .0001), and MPTA (1.4° vs 0.1°; P = .002). Conclusion: This study showed that the affected knees of patients with chronic ACL deficiency (≥5 years) had higher medial and lateral PTS compared with the unaffected contralateral knees. Therefore, when planning ACL reconstruction for patients with a history of long-term ACL deficiency, it is crucial to measure the preoperative PTS accurately.

Prediction of semitendinosus and gracilis autograft sizes for ACL reconstruction.

PURPOSE: The aim of this study was to predict the hamstring graft sizes prior to anterior cruciate ligament reconstruction surgery in adults by using preoperative magnetic resonance imaging (MRI). METHODS: Fifty-one patients with anterior cruciate ligament rupture were prospectively evaluated. Diameter and cross-sectional areas of the gracilis and the semitendinosus tendons at two different levels were measured separately by preoperative MRI. In surgery, harvested gracilis and semitendinosus tendons were measured individually (2-stranded) and together (4-stranded) by using a graft sizing block. Radiological and operative sizes of the grafts were compared by Pearson's correlation test. ROC analysis was done to determine a possible cutoff value for the preoperative measurements. RESULTS: There were statistically significant correlations between the MR cross-sectional areas of gracilis, semitendinosus, gracilis + semitendinosus and intraoperative graft sizes of 2-stranded gracilis, 2-stranded semitendinosus and 4-stranded gracilis + semitendinosus tendons [P < 0.05]. No significant correlation was observed between the MR diameters of the gracilis, semitendinosus, gracilis + semitendinosus tendons and intraoperative graft sizes of 2-stranded gracilis, 2-stranded semitendinosus and 4-stranded gracilis + semitendinosus tendons [n.s]. CONCLUSION: Cross-sectional areas of the hamstring tendons in MR images can be used to estimate the sizes of hamstring grafts prior to anterior cruciate ligament reconstruction surgery which may be very helpful to predict possible graft insufficiencies and take precautions if needed. LEVEL OF EVIDENCE: Level IV.

Pretzel knot compared with standard suture knots.

PURPOSE: Aim of this paper is to compare the biomechanical properties of the Pretzel knot with the selected arthroscopic knots and to test the mechanical safety of this knot. The hypothesis was that the Pretzel knot may have equal or better mechanical properties than the arthroscopic knots tested in this study. METHODS: SMC, Giant, Dines, Nicky's, Tennessee Slider knots were chosen for comparison. Original and backed configuration of knots were prepared with no. 2 braided polyester sutures. Cyclic loading and load to failure tests were performed. Parameters tested were loop security, maximum elongation and load at failure. Number of steps needed for preparation of each knot was also recorded. One-way ANOVA for repeated measures was performed for all knots. RESULTS: Steps needed for preparation were 2 for Pretzel and Tennessee Slider, 3 for Nicky's, SMC and Dines and 4 for Giant. The Pretzel knot in original configuration had significantly better loop security compared to SMC, Dines, Nicky's and Tennessee knots (P = 0.01). Loads at failure were not significantly different between knots in their original configurations. Giant and Dines knots showed better maximum elongations in cyclic loading (P = 0.0059) and load to failure tests (P = 0.0001). Backing up the knots with 3-RHAPs eliminated most of these significant differences. CONCLUSIONS: Clinically, simplicity and safety are two important components in arthroscopic knot tying. Despite its simple configuration, Pretzel knot has some similar and increased mechanical properties compared to the tested knots that are widely used.

Clinical outcome comparison of suprapectoral and subpectoral tenodesis of the long head of the biceps with concomitant rotator cuff repair: A systematic review.

BACKGROUND: Simultaneous repairs of rotator cuff and biceps tenodesis can be managed by tenodesis of long head of biceps tendon to a subpectoral or suprapectoral area. This review investigated long head of biceps tendon tenodesis with concomitant rotator cuff repair and evaluated the clinical outcomes and incidences of complications based on tenodesis location. METHODS: Medline, Cochrane, and Embase databases were searched for published, randomized or nonrandomized controlled studies and prospective or retrospective case series with the phrases "suprapectoral," "subpectoral," "tenodesis," and "long head of biceps tendon". Those with a clinical evidence Level IV or higher were included. Non-English manuscripts, review articles, commentaries, letters, case reports, and sole long head of biceps tendon tenodesis articles were excluded. RESULTS: From 481 studies, 13 were chosen. In total, 1194 subpectoral and 2520 suprapectoral tenodesis cases were investigated. Postoperative Constant-Murley and American Shoulder and Elbow Surgeons mean scores showed similar good results. In terms of complication incidences, while transient nerve injuries were more commonly seen in patients with subpectoral tenodesis, persistent bicipital pain and Popeye deformity are mostly seen in patients with suprapectoral tenodesis. DISCUSSION: Biceps tenodesis to suprapectoral or subpectoral area with concomitant rotator cuff repair demonstrated similar outcomes. Popeye deformity and persistent bicipital pain were higher in suprapectoral area and transient neuropraxia was found to be higher in subpectoral area.Level of evidence: IV.

Return to sport soccer after anterior cruciate ligament reconstruction: ISAKOS consensus.

INTRODUCTION: Many factors can affect the return to pivoting sports, after an Anterior Cruciate Ligament Reconstruction. Prehabilitation, rehabilitation, surgical and psychological aspects play an essential role in the decision to return to sports. The purpose of this study is to reach an international consensus about the best conditions for returning to sports in soccer-one of the most demanding level I pivoting sports after anterior cruciate ligament (ACL) reconstruction. METHODS: 34 International experts in the management of ACL injuries, representing all the Continents were convened and participated in a process based on the Delphi method to achieve a consensus. 37 statements related to ACL reconstruction were reviewed by the experts in three rounds of surveys in complete anonymity. The statements were prepared by the working group based on previous literature or systematic reviews. Rating agreement through a Likert Scale: strongly agree, agree, neither agree or disagree, disagree and strongly disagree was used. To define consensus, it was established that the assertions should achieve a 75% of agreement or disagreement. RESULTS: Of the 37 statements, 10 achieved unanimous consensus, 18 non-unanimous consensus and 9 did not achieve consensus. In the preoperative, the correction of the range of motion deficit, the previous high level of participation in sports and a better knowledge of the injury by the patient and compliance to participate in Rehabilitation were the statements that reached unanimous consensus. During the surgery, the treatment of associated injuries, as well as the use of autografts, and the addition of a lateral extra-articular tenodesis in some particular cases (active young athletes, <25 years old, hyperlaxity, high rotatory laxity and revision cases) obtained also 100% consensus. In the postoperative period, psychological readiness and its validation with scales, adequate physical preparation, as well as not basing the RTSS purely on the time of evolution after surgery, were the factors that reached unanimous Consensus. CONCLUSIONS: The consensus statements derived from this international ISAKOS leaders, may assist clinicians in deciding when to return to sports soccer in patients after an ACL reconstruction. Those statements that reached 100% consensus have to be strongly considered in the final decision to RTS soccer.

The effect of therapeutic ultrasound on metallic implants: a study in rats.

OBJECTIVE: To investigate whether therapeutic ultrasound (US) use over metallic implants has the potential for adverse effects as a result of greater temperature increases at the tissue-metal interface. DESIGN: A randomized controlled trial. SETTING: A research laboratory. ANIMALS: Sprague-Dawley rats (N=40; weight, 230-300g) were used and divided into 3 study groups. INTERVENTIONS: In group 1, both limbs of 10 rats were used for evaluation of temperature changes. Metal pins were placed into the femur of the left limb, and the right limbs were used as controls. A thermal sensor was placed into the medulla to record the elevation of tissue temperature during US application. In groups 2 and 3 with 15 rats in each, a midshaft femoral fracture was produced, and intramedullary fixation was performed with metal pins. Group 2 received US treatment for 5 minutes daily and continued for 27 days. Group 3 served as controls. MAIN OUTCOME MEASURES: The rats in groups 2 and 3 were killed on postoperative day 30. The specimens were evaluated by radiology, histopathology, and biomechanics. RESULTS: The presence of metal in bone did not cause an increased temperature rise. US application did not increase or decrease callus formation, and there was no tissue necrosis. The average removal torques of pins in groups did not show a significant difference. CONCLUSIONS: Internal fixation with metallic implants may not be a contraindication for therapeutic US treatment.

The effect of irrigation solution at different temperatures on articular cartilage metabolism.

PURPOSE: The purpose of this study was to determine the effects of saline solution at different temperatures on the metabolism of chondrocytes. METHODS: Porcine osteochondral explants were precultured under laboratory conditions. The cartilage explants were placed in saline solution. Twenty-four explants were randomly divided into 4 groups. Explants were immersed at 4°C group I, at room temperature (24°C) in group II, at normal knee temperature (32°C) in group III, and at near-core body temperature (37°C) in group IV. All specimens were immersed for 2 hours. Lactate and proteoglycan production and RNA yield analysis were performed to evaluate the changes in cartilage metabolism at different temperatures. RESULTS: Explants immersed in cold (4°C) saline solution showed the significantly lowest RNA yields, lactate production, and proteoglycan content. Explants immersed in cold solutions (4°C and 24°C) showed significantly lower RNA yields, lower lactate production, and lower proteoglycan content than explants in warmer solution groups (32°C and 37°C). CONCLUSION: The findings of this study suggest that short-term exposures to cold including room temperature may have markedly detrimental effects on chondrocyte function. Our findings also indicate that exposures to cold saline solution suppress chondrocyte metabolism and RNA synthesis. CLINICAL RELEVANCE: Using warmer irrigation solution that is closer to body temperature is more physiologic and causes less ultrastructural damage than colder solution.

Adhesion reduction after knee surgery in a rat model by mitomycin C.

The purpose of this study was to investigate the effect of Mitomycin C on reduction in intra-articular fibrotic adhesion formation after knee surgery. Twenty female Wistar Albino rats were divided into two equal study groups. After skin incision, the right knees of animals were opened through a medial parapatellar approach, and the medial and lateral sides of the femoral condyle were exposed. A partial capsulotomy and synovectomy were performed. In group I, Mitomycin C was applied in the articular cavity of rats after hemostasis. An identical volume of sterile normal saline was applied in group II, which served as controls. All rats received weekly (6 weeks) intra-articular both Mitomycin C and saline starting from the day of operation. Animals were killed at 45 days after surgery. The presence and severity of osteo-capsular adhesion was assessed with both macroscopic and microscopic adhesion scoring systems. Results of macroscopic observations showed a significant reduction in both incidence and severity of adhesions in group I compared to group II. Histologically, adhesions in group I were thinner with less collagenic fibers. Microscopic determination of adhesion formation was less in group I, and the difference between groups was statistically significant. Our results suggest that post-operative administration of Mitomycin C may be considered a promising preventive therapy for the reduction in fibro-adhesive scars and consequent stiffness after knee surgery.

Validation of ultrasound imaging for Achilles entheseal fibrocartilage in bovines and description of changes in humans with spondyloarthritis.

BACKGROUND: Entheseal fibrocartilage (EF) derangement is hypothesised to be pivotal to the pathogenesis of spondyloarthritis. Ultrasound is useful for visualisation of the enthesis but its role in EF visualisation is uncertain. This work aimed to demonstrate face and content validity of ultrasound for EF visualisation both by bovine histological evaluation and EF imaging in spondyloarthritis. METHODS: Achilles enthesis of 18 bovine hindfeet was visualised using a MyLab 70 ultrasound machine. The presence of tissue with EF characteristics was documented and histological confirmation was performed on five randomly selected sections using Masson trichrome staining. Ultrasound of the Achilles tendon (AT) was performed in 19 patients with spondyloarthritis and 21 healthy controls (HC). RESULTS: The bovine EF could be visualised in all cases and seen as a thin, uncompressible, well-defined, anechoic layer between the hyperechoic bone and the hyperechoic fibrils of the enthesis both in longitudinal and transverse scans. This region corresponded to EF on histological examination. The same pattern of low signal corresponding to EF location was seen in 17/19 patients and all HC. Discontinuities of the anechoic layer around the erosions and enthesophytes were observed in the spondyloarthritis group. The thickness of the anechoic layer was not significantly different in spondyloarthritis and HC (0.5 ± 0.1 vs 0.5 ± 0.2 mm, p=0.9) whereas the thickness of the EF was greater in men (0.6 ± 0.2 vs 0.5 ± 0.1 mm; p=0.009) compared with women. CONCLUSION: Ultrasound can visualise EF of the AT insertion, which can be abnormal in cases of spondyloarthritis. This has implications for a better understanding of enthesopathy.