The natural course of shoulder instability and treatment trends: a systematic review.

BACKGROUND: The natural course of shoulder instability is still not entirely clear. We aimed in this review to analyse the current scientific evidence of the natural history of shoulder instability. MATERIALS AND METHODS: A systematic review of the English literature was performed using the PubMED database throughout January 2014. This review was guided, conducted and reported according to PRISMA criteria. The criteria for inclusion in the study were (1) the article was written in English, (2) the level of evidence was 1-4, (3) the article was available in full text, (4) the article investigated the natural history or course of shoulder instability, the outcome of non-operative management, or the regression of the shoulder symptoms to the mean. The methodological quality of each included study was individually assessed using a newly developed general assessment tool-Assessing the Methodological Quality of Published Papers (AMQPP). RESULTS: Eight articles related to shoulder instability met the inclusion criteria. Four papers were considered high-quality studies (evidence level 1 and 2). One paper assessed the natural history and the natural course of shoulder instability directly. The other studies indirectly assessed the natural history by studying non-operative and operative therapy trends. We found no articles which clearly referred to the role of 'regression to the mean'. CONCLUSION: Following the natural history and the implementation of standardised non-operative treatment programmes are an effective therapy and superior to surgery in many cases. However, primary acute shoulder dislocation in young active individuals partaking in demanding physical activities could benefit from early surgical intervention. The AMQPP score works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily. The AMQPP scoring system is still open for further development and expansion. Level of evidence Level IV.

[Rotator cuff repair: single- vs double-row. Clinical and biomechanical results]. / Rekonstruktion der Rotatorenmanschette: Single-row oder Double-row. Klinische und biomechanische Ergebnisse.

BACKGROUND: The goal of rotator cuff repair is a high initial mechanical stability as a requirement for adequate biological recovery of the tendon-to-bone complex. Notwithstanding the significant increase in publications concerning the topic of rotator cuff repair, there are still controversies regarding surgical technique. OBJECTIVES: The aim of this work is to present an overview of the recently published results of biomechanical and clinical studies on rotator cuff repair using single- and double-row techniques. MATERIALS AND METHODS: The review is based on a selective literature research of PubMed, Embase, and the Cochrane Database on the subject of the clinical and biomechanical results of single- and double-row repair. RESULTS: In general, neither the biomechanical nor the clinical evidence can recommend the use of a double-row concept for the treatment for every rotator cuff tear. Only tears of more than 3 cm seem to benefit from better results on both imaging and in clinical outcome studies compared with the use of single-row techniques. CONCLUSIONS: Despite a significant increase in publications on the surgical treatment of rotator cuff tears in recent years, the clinical results were not significantly improved in the literature so far. Unique information and algorithms, from which the optimal treatment of this entity can be derived, are still inadequate. Because of the cost-effectiveness and the currently vague evidence, the double-row techniques cannot be generally recommended for the repair of all rotator cuff tears.

Effect of single- and double-row rotator cuff repair at the tendon-to-bone interface: preliminary results using an in vivo sheep model.

INTRODUCTION: The clinical superiority of the double-row technique is still a subject of controversial debate in rotator cuff repair. We hypothesised that the expression of different collagen types will differ between double-row and single-row rotator cuff repair indicating a faster healing response by the double-row technique. MATERIALS AND METHODS: Twenty-four mature female sheep were randomly assembled to two different groups in which a surgically created acute infraspinatus tendon tear was fixed using either a modified single- or double-row repair technique. Shoulder joints from female sheep cadavers of identical age, bone maturity, and weight served as untreated control cluster. Expression of type I, II, and III collagen was observed in the tendon-to-bone junction along with recovering changes in the fibrocartilage zone after immunohistological tissue staining at 1, 2, 3, 6, 12, and 26 weeks postoperatively. RESULTS: Expression of type III collagen remained positive until 6 weeks after surgery in the double-row group, whereas it was detectable for 12 weeks in the single-row group. In both groups, type I collagen expression increased after 12 weeks. Type II collagen expression was increased after 12 weeks in the double-row versus single-row group. Clusters of chondrocytes were only visible between week 6 and 12 in the double-row group. CONCLUSIONS: The study demonstrates differences regarding the expression of type I and type III collagen in the tendon-to-bone junction following double-row rotator cuff repair compared to single-row repair. The healing response in this acute repair model is faster in the double-row group during the investigated healing period.

[The effect of arthroscopic debridement and conservative treatment in knee osteoarthritis: Results of a 5-year follow-up and literature review]. / Die Behandlung moderater Kniegelenksarthrosen durch arthroskopisches Gelenkdebridement: 5-Jahres-Ergebnisse und systematisches Review.

PURPOSE: This study is aimed to compare the effects of arthroscopic joint debridement over a 5-year period in a clearly defined patient population (only grade III knee osteoarthritis, history < 2 years). MATERIAL AND METHODS: A total of 96 patients (50 male and 46 female) underwent arthroscopic knee debridement for knee OA. The main criteria for inclusion were osteoarthritis grade III (Kellgren-Lawrence score) and a maximal history of 2 years. RESULTS: The subjective complaints and the knee-related quality of life were estimated by the KOOS (knee injury and osteoarthritis outcome score). The score increased significantly within the 1 to 3 rd year post operation. After this interval the mean points of the score declined. But after 5 years the KOOS was higher in comparison to the baseline dates. Patients who had undergone conservative treatment at baseline had a significantly different KOOS than patients in the arthroscopy group. Over time, patients in the arthroscopy group had fewer complaints than patients in the conservative treatment group. In both groups, the results decreased over time. A total of 17 patients (17.2 %) needed a conversion to total endoprothetic replacement. The mean time-interval between index operation and conversion was 56.6 (95 % CI 54.4 - 58.4) months. CONCLUSIONS: In middle stages of knee OA, arthroscopic joint debridement can effectively reduce subjective complaints. Because this treatment does not stop the process of OA, the improvements decrease over time.

Mechanical testing of different knot types using high-performance suture material.

PURPOSE: This laboratory study aimed to evaluate the loop security, knot security, cyclic loading resistance and load-to-failure rate of three different knot types with establishing a new experimental set-up. Additionally, the mode of failure of each knot was evaluated. METHODS: With the use of nonabsorbable, braided polyethylene sutures, USP size No. 2 [Hi-Fi®; ConMed Linvatec], the arthroscopic knot types Dines, SMC as well as the surgeon's knot were tested using a material testing machine. The knots were tied openly as well as arthroscopically. The set-up enables testing of knot configurations while eliminating friction between knot loop and its suspension points. Including all test procedures, a total of 216 knots were tested. RESULTS: All openly tied knot types and ten of each type of arthroscopically tied knots resisted against cyclic loading of 1,000 cycles. With subsequent load-to-failure testing, openly tied knot types achieved significantly higher values of tensile strength than arthroscopically tied knots. Regarding clinical failure, defined as an elongation of 3 mm, Dines knot reached highest loop as well as knot security. Knot slippage was the most common failure mechanism at an elongation of 3 mm, whereas suture breakage was evaluated most at an elongation of 6 mm. CONCLUSIONS: The new experimental set-up confirms the loop security of arthroscopic knot types. Using a knot pusher clinically is a key factor to attain this as compared to openly hand-tied techniques. The Dines knot presented the highest reliability. It may provide a secure tissue healing during rehabilitation and consequently can be recommended for clinical application.

[Evaluation of cartilage degeneration by near infrared spectroscopy (NIRS): methodical description and systematic literature review]. / Bestimmung des Degenerationsgrads am hyalinen Gelenkknorpel durch Nah-Infrarot-Spektroskopie (NIRS): Methodenbeschreibung und Literaturübersicht.

Damage to hyaline cartilage is the most important pathophysiological tool in the development of osteoarthritis. Cartilage lesions are the most frequent pathological findings during arthroscopic operations. Arthroscopies as well as magnetic resonance tomography are gold standards for detection of cartilage lesions. But the arthroscopic evaluation of cartilage lesions is descriptive and subjective only. The surgeon is able to differentiate between intact cartilage surface, softening, superficial or deep fissure or flake and finally a complete defect. In routine arthroscopy the grading mostly is made by use of different scores [e.g. ICRS (International Cartilage Repair Society), Outerbridge, Insall, Jäger-Wirth or others]. Because the arthroscopic evaluation is subjective the reliability of this method is poor. Spectroscopic methods are established for evaluation of different tissue diseases in different indications. NIRS (near infrared spectroscopy) has become an important method for medical diagnostics in the last years. NIR is very energy-rich and suitable for glass fibre transport without relevant reduction. Insofar this technology may be ideal for endoscopic procedures. Our systematic literature review reveals that NIRS is a sufficient method for an objective diagnosis of cartilage lesions. In the current work we demonstrate an NIRS-based device for intraoperative, real-time cartilage evaluation. Furthermore, we discuss the possible clinical consequences from such measurements.

[Cartilage regeneration after high tibial osteotomy. Results of an arthroscopic study]. / Knorpelregeneration nach valgisierender Tibiakopfosteotomie. Ergebnisse einer arthroskopischen Studie.

AIM: High tibial osteotomy (HTO) has been established as an effective method for the treatment of unicondylar knee osteoarthritis. This study was undertaken to quantify the potential for restoration of cartilage lesions or defects after HTO in relation to different cartilage treatment modalities. Control arthroscopy was undertaken to identify the cartilage lesions within the knee joint 1.5 years after medial opening wedge osteotomy. MATERIAL AND METHOD: A total of 135 patients (72 male and 63 female) had undergone medial-opening high tibial osteotomy and arthroscopy. The mean age at operation was 48.8 (36 to 65) years. All HTO were fixed with an angle-stable, mobile spacer-containing plate (HTO-Platte, Königsee, Deutschland). All HTO were combined with a simultaneous arthroscopy. Grade III cartilage lesions had undergone either shaving or temperature-controlled chondroplasty (Paragon ArthroW Austin, TX, USA). In some case these cartilage lesions had remained untreated. Control arthroscopy and removal of the implants was performed 1.5 years after HTO. The cartilage lesions were graded accordingly to the ICRS guidelines (International Cartilage Repair Society). RESULTS: The KOOS at HTO was 49.9 (SD 10.6) points. We observed at follow-up a mean increase from 66.1 (SD 28.8, 95 % CI: 61.2-71.1) points. The KOOS at follow-up was 16.1 (SD 29.8) points. There was no delayed union of the HTO space. Before HTO the varus angle was 10.4° (SD 3.9 range 5 to 20°). The correction angle was 13.6° (SD 4.4, 95 % CI: 12.9-14.4°). Finally we determined a valgus angle of -3.2° (SD 1.8 minimum 0° varus, maximum -6° valgus. The clinical outcome (KOOS) significantly (p < 0.001) correlated (R = 0.605) with the extension of valgisation. Patients with a valgus angle of 3° and more had the best outcome. Of the grade III lesions 40.4 % in the medial femoral condyle and 62.3 % in the medial tibial plateau increased to grade II or I lesions. In 13.1 % of the medial femoral condyle and 8.5 % of medial tibial plateau cases we found complete (grade IV) defects at control arthroscopy. The highest rate of regenerations was detected after temperature-controlled chondroplasty. The worst results were produced after mechanical debridement. Microfracturing of complete defects produced regeneration in about ⅔ in the medial femoral condyle and about ⅓ in the medial tibial plateau. No increase was observed within the lateral or patello-femoral compartment. No correlation was seen between cartilage regeneration and outcome. The extension of valgisation did not influence the cartilage regeneration. CONCLUSIONS: The main effect of the HTO is the shift of the weight-bearing line from the arthritic compartment to the opposite femorotibial healthy one. In addition, HTO also produces a partial restoration of cartilage lesions. Deep cartilage lesions (grade III) restore in about 60 % of the cases after HTO. The worst restoration is found after mechanical shaving. This method should be avoided in the future. The best restoration was found in deep lesions after thermochondroplasty. Furthermore, in about half of the patients with complete (grade IV) defects, microfracturing caused the formation of fibrocartilaginous regenerates. This procedure should always be performed if possible.

[Treatment of locked chronic posterior dislocation of the shoulder]. / Therapie der verhakten chronischen hinteren Schulterluxation.

INTRODUCTION: The posterior locked shoulder dislocation is a rare injury that is often associated with an impression fracture of the anteromedial aspect of the humeral head. The majority of posterior shoulder dislocations are missed on the initial examination. METHODS: We demonstrate the case of an athlete, who presented with a posterior shoulder dislocation after a trauma two months ago. RESULTS: The patient was treated with a M. subscapularis transfer in the reverse-hill-sachs-lesion. DISCUSSION: The diagnosis of the posterior shoulder dislocation remains a problem in the clinical setting. Treatment is based on the size defect of the anteromedial humeral head. Different treatment options are still controversially discussed. CONCLUSION: To diagnose a posterior shoulder dislocation correctly a standard clinical and radiological assessment is necessary.

[The prevalence of radiological osteoarthritis in relation to age, gender, birth-year cohort, and ethnic origins]. / Die Prävalenz der radiologischen Gonarthrose in Bezug zu Lebensalter, Geschlecht, Jahrgangskohorte und ethnischer Zugehörigkeit. Eine Metaanalyse.

AIM: This metaanalysis was performed to evaluate the prevalence of the radiological assessed knee osteoarthritis in the whole community. MATERIALS AND METHODS: Medical databases (Medline, EMBASE, Cochrane) were searched for the strategy: ["Osteoarthritis" and "Knee" and "Prevalence"]. The deadline for the search was 31.12.2009. Two investigators (first and senior author) independently made the selection from 17 studies (from a total of 1428) according to the inclusion criteria: a cross-sectional study of the whole community, radiological investigation and definition of knee ROA by an established radiological score. Only studies in English or German language were evaluated. Effect sizes (event rate, odds ratio [OR] and confidence interval [CI]) were calculated by the software "Comprehensive Metaanalysis V2". Study heterogeneity (I2) was determined accordingly to Higgins. RESULTS: The kappa index for interobserver validity was k = 0.948. All studies judged the grade of osteoarthritis according to the Kellgren-Lawrence (KL) score. For calculation of knee ROA KL grades 2+ were estimated only. The total prevalence of knee ROA was 24.3 % (CI 23.4-25.2 %). The whole prevalence in male patients was 24.3 % (CI 23.4-25.2 %); I2 = 59.4 (p = 0.002) and in female patients 32.6 % (CI 31.8-33.4 %); I2 = 49,1 (p < 0.001). Younger male patients (age 50-) had a prevalence of 5.6 (CI 4.5-6.8). In older patients (80+) the male prevalence was 44.5 % (CI 39.6-49.5 %). In this age group female patients had a prevalence of 71.6 % (CI 67.6-75.3 %). The higher prevalence of knee ROA in female patients was significant (OR = 1.8 [1.7-1.9]; I2 = 46.0 [p < 0.001]). The prevalence of knee ROA was higher in male Asians compared with male Caucasians (OR = 1.1, CI 0.9-1.2; p = 0.080) in tendency. This difference was significant in female patients (OR = 2.2; CI 2.0-2.4; p < 0.001). Furthermore another trend was evaluated. Female patients (70-79 years) from the birth-year cohort 1920- had a prevalence of 37.8 % (CI 35.9-39.7)%. In contrast female patients from the birth-year cohort 1920 had a prevalence of 62.8 % (CI 60.8-64.8 %) at 70-79 years. This difference was significant (OR = 2.8; CI 2.5-3.1; p < 0.001). CONCLUSIONS: This investigation confirms the high prevalence of knee ROA. The evaluated data may serve as a reference for medical or scientific investigations in the future.

[The modular endoprosthetic system Munich-Luebeck (MML): potential applications and results in the lower extremities]. / Modulares Endoprothesensystem München-Lübeck (MML) : Anwendungsmöglichkeiten und Ergebnisse an den unteren Extremitäten.

The modular endoprosthetic system Munich-Luebeck (MML) has been in clinical use since 1994. A total of 2.118 pelvic and lower extremity surgeries using the MML system were carried out up until 2010. The modular construction allows substituting or bridging any kind of bone defect. We analyzed 572 operative interventions, which were performed in 5 centers. The most frequent indications were tumors (50.3%) followed by revision arthroplasty due to loosening, periprosthetic fractures, and joint resection surgery due to infection (43.3%). Proximal and distal femoral replacement amounted to 78% of cases, whereas partial pelvic replacement accounted for 10.4% of the cases. Complications were reported in 27.27% of the cases, where dislocations (14.9% of the cases with simultaneous hip replacement) and infections (10.48%) were the most common, as expected. Revision surgery was necessary in 140 (24.8%) of the 572 patients, of which 68 were partial or total replacement of the implants, 16 removal of the implants and 10 above-knee amputations or rather exarticulations of the hip.

Intraosseous foreign body granuloma in rotator cuff repair with bioabsorbable suture anchor.

Biodegradable implants lead to problems such as cyst formation, soft-tissue inflammation, loose implant fragments or local osteolysis. This report represents the first published case of an intraosseous foreign body granuloma in the humeral head after arthroscopic rotator cuff tear fixation with a poly-L: -lactide (PLLA) suture anchor. A 48-year-old female patient presented with pain in her right shoulder. A refixation of her right supraspinatus tendon with a biodegradable suture anchor was performed 11 months ago at an external hospital. Laboratory tests showed normal values for C-reactive protein, leukocytes and the erythrocyte sedimentation rate. No signs of infection or instability were noted. The visual analogue scale (VAS) was 8, the simple shoulder test (SST) was 4 and the American shoulder and elbow surgeons score (ASES) was 44. Plain radiographs showed high lucency in the area of the tuberculum majus. MRI showed an intra- and extraosseous mass surrounded by fluid in this area. Surgical care involved arthroscopic debridement and removal of the suture anchor. Histological examination revealed a foreign body granuloma. At the 18-month follow-up the patient was nearly pain-free. The VAS was 2, SST was 10 and ASES was 88. Foreign body granulomas are a well known but rarely described complication that arises after the use of biodegradable suture anchors in shoulder surgery. Every patient presenting with shoulder pain after usage of a biodegradable fixation material should be evaluated closely. Orthopaedic surgeons should be aware of the possibility of delayed foreign body reactions, especially after using PLLA anchors.

Initial load-to-failure and failure analysis in single- and double-row repair techniques for rotator cuff repair.

AIM: This experimental study aimed to compare the load-to-failure rate and stiffness of single- versus double-row suture techniques for repairing rotator cuff lesions using two different suture materials. Additionally, the mode of failure of each repair was evaluated. METHOD: In 32 sheep shoulders, a standardized tear of the infraspinatus tendon was created. Then, n = 8 specimen were randomized to four repair methods: (1) Double-row Anchor Ethibond coupled with polyester sutures, USP No. 2; (2) Double-Row Anchor HiFi with polyblend polyethylene sutures, USP No. 2; (3) Single-Row Anchor Ethibond coupled with braided polyester sutures, USP No. 2; and (4) Single-Row Anchor HiFi with braided polyblend polyethylene sutures, USP No. 2. Arthroscopic Mason-Allen stitches were placed (single-row) and combined with medial horizontal mattress stitches (double-row). All specimens were loaded to failure at a constant displacement rate on a material testing machine. RESULTS: Group 4 showed lowest load-to-failure result with 155.7 +/- 31.1 N compared to group 1 (293.4 +/- 16.1 N) and group 2 (397.7 +/- 7.4 N) (P < 0.001). Stiffness was highest in group 2 (162 +/- 7.3 N/mm) and lowest in group 4 (84.4 +/- 19.9 mm) (P < 0.001). In group 4, the main cause of failure was due to the suture cutting through the tendon (n = 6), a failure case observed in only n = 1 specimen in group 2 (P < 0.001). CONCLUSIONS: A double-row technique combined with arthroscopic Mason-Allen/horizontal mattress stitches provides high initial failure strength and may minimize the risk of the polyethylene sutures cutting through the tendon in rotator cuff repair when a single load force is used.

Arthroscopic evaluation of the ACL double bundle structure.

In order to describe the arthroscopic presence of the double bundle structure and to evaluate the value of different portals in knee arthroscopy, we assessed the AM and PL bundle anatomy. We prospectively examined the knees of 60 patients undergoing arthroscopic surgery for pathology unrelated to the ACL. Arthroscopy was performed in a two portal technique using an anterolateral (ALP) and an anteromedial (AMP) portal. With the arthroscope in the ALP, we could distinguish an AM and PL bundle in 28%. Switching the arthroscope to the AMP, differentiation of the bundles was possible in 67%. In all remaining cases visualization of the PL bundle was possible after retraction of the AM bundle. Use of AMP increased visualization of the PL bundle. It seems reasonable to perform arthroscopy for ACL reconstruction with the arthroscope in the AMP and to establish an additional medial working portal to increase the visualization of the femoral ACL insertion sites for optimal femoral tunnel placement.

Comparative evaluation of the tendon-bone interface contact pressure in different single- versus double-row suture anchor repair techniques.

The aim of the study was to evaluate the time zero contact pressure over a defined rotator cuff footprint using different repair and stitch techniques in an established sheep model. Forty fresh-frozen sheep shoulders were randomly assigned to five repair groups: single-row repair using simple stitches (SRA-s), single-row repair using horizontal mattress stitches (SRA-m), and single-row repair using arthroscopic Mason-Allen stitches (SRA-ama). Double-row repair was either performed with a combination of simple and horizontal mattress stitches (DRA-sm) or with arthroscopic Mason-Allen/horizontal mattress stitches (DRA-amam). Investigations were performed using a pressure-sensitive film system. The average contact pressure and pressure pattern were measured for each group. Contact pressure was lowest in SRA-m followed by SRA-s. SRA-ama showed highest contact pressure of all single-row treatment groups (P < 0.05). DRA-amam presented the highest overall contact pressure (P < 0.05), whereas DRA-sm exerted contact pressure equal to that of SRA-ama. Both double-row techniques showed the most expanded pressure pattern. Average contact pressures for the more complex single- and double-row techniques utilizing arthroscopic Mason-Allen stitches were greater than were those of the repair techniques utilizing simple and horizontal mattress stitches. However, the contact pattern between the anchors could be increased by using the double-row technique, resulting in more footprint coverage compared to patterns utilizing the single-row techniques. These results support the use of the more complex arthroscopic Mason-Allen stitches and may improve the environment for healing of the repaired rotator cuff tendon.

Anti-inflammatory effects of atorvastatin on peripheral blood mononuclear cells and synovial fibroblasts in rheumatoid arthritis.

OBJECTIVE: Statins, such as atorvastatin (ATV), are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors known to exert lipid-lowering but also anti-inflammatory, effects. In this study, we analysed the in vitro effects of ATV on peripheral blood mononuclear cells (PBMCs) and fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA), a chronic inflammatory joint disease. METHODS: PBMCs isolated from 25 RA patients and 20 healthy blood donors were stimulated in vitro with 0.1 microM ATV for 24 h. PBMC cultures were analysed for cell surface markers to characterize T-cell subtypes (CD4, CD8, CD69, HLA-DR) by flow cytometry and for T helper cell type 1 (Th1) and type 2 (Th2) cytokines [interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-10] in culture supernatants by enzyme-linked immunosorbent assay (ELISA). Furthermore, RNA isolated from ATV-stimulated RA-FLS pre- and post-ATV stimulation was analysed by microarray and quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Flow cytometric analysis of T-cell subsets revealed no significant differences for CD4, CD8, CD69, and HLA-DR surface marker expression of PBMCs in RA patients and healthy controls after ATV stimulation. However, the proportion of IFN-gamma expressing CD4+ T cells and the IFN-gamma cytokine concentrations in culture supernatants were significantly reduced in T-cell cultures from RA patients. In ATV-stimulated FLS a significant downregulation of proinflammatory cytokine (IL-6) and chemokine (IL-8) expression was detected (p<0.001). CONCLUSIONS: Our study demonstrates a marked in vitro anti-inflammatory activity of ATV in RA including a systemic effect on a pathogenic CD4+ T-cell population (Th1) and a local effect on FLS. These findings may provide a scientific rationale for statins as add-on therapy in RA.

Cell biological and biomechanical evaluation of two different fixation techniques for rotator cuff repair.

Our objective was to evaluate the cell biology and biomechanical aspects of the healing process after two different techniques in open rotator cuff surgery - double-loaded bio-absorbable suture anchors combined with so-called arthroscopic Mason-Allen stitches (AAMA) and a trans-osseous suture technique combined with traditional modified Mason-Allen stitches (SMMA). Thirty-six mature sheep were randomized into two repair groups. After 6, 12, or 26 weeks, evaluation of the reinsertion site of the infraspinatus tendon was performed. The mechanical load-to-failure and stiffness results did not indicate a significant difference between the two groups. After 26 weeks, fibrocartilage was sparse in the AAMA group, whereas the SMMA group showed the most pronounced amount of fibrocartilage. We found no ultrastructural differences in collagen fiber organization between the two groups. The relative expression of collagen type II mRNA in the normal group was 1.11. For the AAMA group, 6 weeks after surgery, the relative expression was 55.47, whereas for the SMMA group it was 1.90. This in vivo study showed that the AAMA group exhibited a tendon-to-bone healing process more favorable in its cell biology than that of the traditional SMMA technique. Therefore, the AAMA technique might also be more appropriate for arthroscopic repair.

Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material.

The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P < 0.001). The ultimate tensile strength in double-row specimens was significantly higher than in others (P < 0.001). There was no significant variation in using different suture material (P > 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

[Evaluation of cartilage defects in the knee: validity of clinical, magnetic-resonance-imaging and radiological findings compared with arthroscopy]. / Diagnostik von Knorpelschäden des Kniegelenks: Validität der klinischen, radiologischen und kernspintomographischen Diagnostik im Vergleich zur Arthroskopie.

BACKGROUND: The study was aimed to evaluate the validity of clinical, radiological and MRI examination for cartilage defects of the knee compared with arthroscopic finding. METHODS: Seven-hundred seventy-two patients who were suffering from knee pain over more than 3 months were evaluated clinical (grinding-sign) and with radiography and magnetic resonance imaging (MRI) and subsequent arthroscopy. RESULTS: The grinding sign had a sensitivity of 0.39. The association of a positive grinding test with high grade cartilage defects was significant (p<0.000). In 97.4% an intact chondral surface correlated with a normal radiological finding. Subchondral sclerosis, exophytes and a joint space narrowing was significantly associated with high grade cartilage defects (p<0.000). The accuracy of MRI was 59.5%. The MRI resulted in an overestimation in 36.6% and an underestimation in 3.9%. False-positive results were significant more often assessed in low-grade cartilage defects (p<0.000). CONCLUSIONS: Clinical signs, x-ray imaging and MRI correlate with arthroscopic findings in cases of deep cartilage lesions. In intact or low-grade degenerated cartilage often results an overestimating of these findings.

The interobserver-validated relevance of intervertebral spacer materials in MRI artifacting.

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium, carbon or cobalt-chrome, which can affect the post-fusion MRI scans. Implant-related susceptibility artifacts can decrease the quality of MRI scans, thwarting proper evaluation. This cadaver study aimed to demonstrate the extent that implant-related MRI artifacting affects the post-fusion evaluation of intervertebral spacers. In a cadaveric porcine spine, we evaluated the post-implantation MRI scans of three intervertebral spacers that differed in shape, material, surface qualities and implantation technique. A spacer made of human cortical bone was used as a control. The median sagittal MRI slice was divided into 12 regions of interest (ROI). No significant differences were found on 15 different MRI sequences read independently by an interobserver-validated team of specialists (P>0.05). Artifact-affected image quality was rated on a score of 0-1-2. A maximum score of 24 points (100%) was possible. Turbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. The carbon, titanium and cobalt-chrome spacers scored 83.3, 62.5 and 50%, respectively. Our scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the control that was independent of artifact dimensions. The carbon spacer had the lowest percentage of susceptibility artifacts. Even with turbo spin echo sequences, the susceptibility artifacts produced by the metallic spacers showed a high degree of variability. Despite optimum sequencing, implant design and material are relevant factors in MRI artifacting.

Functional outcome and general health status in patients after arthroscopic release in adhesive capsulitis.

Frozen shoulder is said to be a self-limiting entity but full recovery often takes more than 2 years. For that, most patients are unwilling to tolerate painful restriction while awaiting resolution. We prospectively investigated 30 patients (16 women, 14 men) for the outcome of arthroscopic capsular release in idiopathic frozen shoulder. Results were determined by the assessment of subjective and objective parameters to estimate both shoulder function and general health status. Symptoms persisted without improvement for a minimum of 6 months of conservative treatment. Preoperative average American shoulder and elbow surgeons score (ASES) was 35, visual analog scale (VAS) to measure pain was 7, and simple shoulder test (SST) was 4. Mean scores of the physical component of SF-36 were considerably reduced. Mean forward elevation was 85 degrees , average abduction was 70 degrees , mean internal rotation was 15 degrees , and mean external rotation was 10 degrees . Patients were followed-up at 6 weeks, 3, 6, 12 months and by a mean of 36 months. Range of motion for all planes improved (P < 0.05). Median VAS reduced to 2, average ASES increased to 91, and SST enhanced to a mean of 10 (P < 0.05). We stated improvement of the physical components in the SF-36 questionnaire in particular bodily pain and the role-physical score. There were no significant differences between the measurements in the early postoperative phase compared to the mid-term follow-up (P > 0.05). Our results demonstrate that arthroscopic release of refractory idiopathic frozen shoulder combined with a gentle manipulation provides reliable expectations for improvement in both clinical and general health status for most patients. We recommend the use of a limb-specific and a general-health-status questionnaire to conclude the benefit of the surgical intervention and contribute the optimization of a therapy concept more effectively.