Gabor J. Puskas

Outcome of pectoralis major transfer for the treatment of irreparable subscapularis tears.

BACKGROUND Chronic tears of the subscapularis tendon with or without associated tears of the supraspinatus and infraspinatus tendons may lead to pain and dysfunction of the shoulder. If conservative treatment fails and repair of the musculotendinous unit is impossible, transfer of the pectoralis major tendon can be attempted to substitute for lost subscapularis function. METHODS Twenty-eight patients underwent a total of thirty consecutive pectoralis major transfers at an average age of fifty-three years. There were twelve isolated subscapularis tears and eighteen subscapularis tears associated with a tear of the supraspinatus or the supraspinatus and infraspinatus. All patients were examined clinically and with standard radiographs. RESULTS The mean relative Constant score increased from 47% preoperatively to 70% at an average of thirty-two months postoperatively (p < 0.0001). The mean Constant scores for pain (p = 0.0009) and activities of daily living (p < 0.0001), the range of forward flexion (p < 0.05), and abduction strength (p = 0.001) also improved. Thirteen patients (14 shoulders) were very satisfied, ten patients (eleven shoulders) were satisfied, two patients (two shoulders) were disappointed, and three patients (three shoulders) were dissatisfied with the result. The average subjective shoulder value increased from 23% preoperatively to 55% postoperatively (p = 0.0009). In patients with a massive tear, the outcome was less favorable when the torn supraspinatus tendon was irreparable, as determined preoperatively or intraoperatively, than when it was reparable (average relative Constant scores, 49% and 79%, respectively; p = 0.002). CONCLUSIONS Pectoralis major transfer results in improvement for patients with an irreparable subscapularis tear with or without an associated reparable supraspinatus tear. If an irreparable subscapularis tear is associated with an irreparable supraspinatus tear, the results are less favorable, and pectoralis major transfer may not be warranted.

Cyr61 Expression in Osteosarcoma Indicates Poor Prognosis and Promotes Intratibial Growth and Lung Metastasis in Mice

Osteosarcoma is the most frequent primary malignant bone tumor in children and adolescents with a high propensity for lung metastasis, the major cause of disease‐related death. Reliable outcome‐predictive markers and targets for osteosarcoma metastasis‐suppressing drugs are urgently needed for more effective treatment of metastasizing osteosarcoma, which has a current mean 5‐year survival rate of approximately 20%. This study investigated the prognostic value and the biological relevance of the extracellular matrix‐associated growth factor Cyr61 of the CCN family of secreted proteins in osteosarcoma and metastasis. The prognostic value of Cyr61 was assessed with Kaplan‐Meier analyses based on Cyr61 immunostaining of a tissue microarray of osteosarcoma biopsies collected from 60 patients with local or metastatic disease. Effects of Cyr61 overexpression on intratibial tumor growth and lung metastasis of the low metastatic human SaOS‐2 osteosarcoma cell line were examined in severe combined immunodeficiency (SCID) mice. Cyr61‐provoked signaling was studied in vitro in nonmanipulated SaOS‐2 cells. Cyr61 immunostaining of osteosarcoma tissue cores correlated significantly (p = 0.02) with poor patient survival. Mice intratibially injected with Cyr61‐overexpressing SaOS‐2 cells showed faster tumor growth and an increase in number and outgrowth of lung metastases and consequently significantly (p = 0.0018) shorter survival than mice injected with control SaOS‐2 cells. Cyr61‐evoked PI‐3K/Akt/GSK3β signaling in SaOS‐2 cells resulted in a subcellular redistribution of the cell cycle inhibitor p21Cip1/WAF1. Cyr61 has considerable potential as a novel marker for poor prognosis in osteosarcoma and is an attractive target for primary tumor‐ and metastases‐suppressing drugs.

Clinical outcome of reverse total shoulder arthroplasty combined with latissimus dorsi transfer for the treatment of chronic combined pseudoparesis of elevation and external rotation of the shoulder

BACKGROUND Reverse total shoulder arthroplasty (RTSA) allows correction of pseudoparesis of elevation caused by irreparable rotator cuff tear but does not address loss of active external rotation. Latissimus dorsi transfer (LDT) is an established procedure for correction of pseudoparesis of external rotation. METHODS Forty-one shoulders of 40 consecutive patients, who were a mean age of 70 years old (range 47-85 years), underwent RTSA combined with LDT for irreparable rotator cuff failure with severe shoulder dysfunction. RESULTS Nine orthopedic complications occurred in 7 of the 41 shoulders. Four shoulders were lost to follow-up, and 5 were excluded from the functional analysis. The mean follow-up of the eligible 32 shoulders with the prosthesis still in place was 53 months (range, 24-105 months). The age-related Constant score increased significantly from a preoperative mean of 45% (range, 16%-80%) to 89% (range, 25%-100%). The mean subjective shoulder value increased from 33% (range, 0%-70%) to 75% (range, 30%-100%). Active external rotation significantly improved from a mean of 4° (range, -30° to 40°) to 27° (range, -10° to 70°). A preoperative external rotation lag sign could be corrected in 25 of the 32 shoulders. For the 16 shoulders with at least 5 years of follow-up, the Constant scores were 47% (range, 16%-80%) preoperatively, 92% (range, 51%-100%) at 2 years, and 94% (range, 57%-100%) at the latest follow-up, and the respective subjective shoulder values were 32% (range, 0%-70%), 73% (range, 30%-100%), and 80% (range, 60%-100%). CONCLUSION If treated with RTSA combined with LDT, patients with pseudoparesis of elevation and pseudoparesis of external rotation can expect an excellent clinical outcome for a period beyond 5 years, provided that complications that require removal of the prosthesis can be prevented.

LacZ transgene expression in the subcutaneous Dunn/LM8 osteosarcoma mouse model allows for the identification of micrometastasis†

More effective treatment of patients with metastasizing osteosarcoma (OS) with a mean 5‐year survival rate of <20% requires more detailed knowledge on the complex mechanisms of metastasis for the design of new drugs, which selectively target metastasizing cells. Moreover, novel diagnostic imaging technology for early detection of metastases is needed. Mouse models, which reproduce human metastasizing OS and allow visualization of single metastatic cells are instrumental for preclinical testing of new pharmaceuticals and diagnostic instruments. Here, the low metastatic Dunn cell line and its highly metastatic LM8 subline, both equipped with a constitutively expressed lacZ gene, were used to improve the well‐established OS models in syngeneic C3H mice to achieve ex vivo visualization of single metastatic cells in affected organs by X‐gal staining. These models, combined with a technique for in situ high quality lung tissue‐maintaining perfusion revealed, as a novel finding, single metastasizing Dunn cells in lung and liver. Importantly, constitutive lacZ gene expression did not affect in vitro and in vivo tumorigenic and metastatic properties of Dunn and LM8 cells. Thus, these improved Dunn and LM8 OS mouse models will in the future serve as a benchmark for the development of new metastasis‐targeting drugs and metastasis‐imaging technology.

Posttraumatic elbow arthritis in the young adult: evaluation and management.

Abstract Degenerative joint disease following trauma to the elbow is difficult to manage in any patient. However, this condition becomes substantially more challenging in the young, active population. Increased activity demands and limited functional capacity of total elbow arthroplasty mean that joint arthroplasty should be regarded as a salvage procedure. The primary goal of treatment is to restore a pain‐free or minimally painful functional joint while preserving future surgical options. This requires accurate assessment of the primary patient complaint, be it terminal pain and stiffness or pain along the entire arc of motion. Patients who report stiffness and pain at terminal motion may benefit from arthroscopic or open osteocapsular débridement. Those with advanced degenerative changes and pain throughout the entire arc of motion may require joint resurfacing with interposition arthroplasty, partial joint arthroplasty, or total joint arthroplasty.

Tensile and Shear Loading Stability of All-Inside Meniscal Repairs An In Vitro Biomechanical Evaluation

Background: Most biomechanical studies for evaluation of the structural properties of meniscal repairs have been performed in tensile loading scenarios perpendicular to the circumferential meniscal fibers. However, meniscal repair constructs are also exposed to shear forces parallel to the circumferential meniscal fibers during healing, particularly in the midportion of the meniscus. Hypothesis: Material properties of meniscal repair devices cannot be extrapolated from tensile to shear load scenarios. Study Design: Controlled laboratory study. Methods: In 84 harvested and isolated bovine lateral menisci following removal of adjacent soft tissue, a standardized vertical lesion was set followed by repair using all-inside flexible (FasT-Fix, FasT-Fix AB, RapidLoc) and rigid (Meniscus Screw, Meniscus Arrow) meniscal repair devices. Vertical and horizontal 2.0 Ethibond sutures were used as controls. The repaired meniscal construct was tested in a tensile (parallel to the axis of the tested repair device) and shear load scenario (perpendicular to the axis of the tested repair device) at 5 mm/min and 37°C environmental temperature. Maximum load to failure, stiffness, and failure mode were recorded. Results: The absolute load to failure values of each repair device in the shear scenario were only marginally different from the tensile load scenario. However, the stiffness of several tested devices was markedly reduced in the shear scenario. In both scenarios, large differences of the load to failure and the stiffness between the implant types up to 5-fold were found (P < .05). The failure mode of several all-inside flexible repair devices was different in the shear versus tensile load scenario, while the failure mode of the rigid systems was similar in both scenarios. Conclusion: All-inside meniscal repair devices exposed to shear load scenarios have comparable maximum loads to failures as tensile load scenarios. However, the stiffness of the majority of the flexible meniscal repair implants in a shear load scenario is markedly reduced. The applied scenario also affects the failure mode in several flexible meniscal repair devices. Clinical Relevance: Meniscal repair devices with sufficient stiffness and stability against shear loads may be favored for meniscal repair, especially within the midportion of the meniscus where shear loads occur during healing.

Do the Traditional and Modified Latarjet Techniques Produce Equivalent Reconstruction Stability and Strength

Background: The Latarjet procedure has been described as a reconstructive option for instability associated with substantial glenoid bone defects. A modification, termed the Congruent-Arc, is thought to improve glenoid reconstruction through better articular congruency and greater bone reconstitution. The strengths of these techniques, however, have not been reported. Purpose/Hypothesis: To compare the fixation stability, strength, glenoid vault load transfer, and joint contact between the Classic and Congruent-Arc techniques. The authors hypothesized that the Classic Latarjet would exhibit inferior joint contact characteristics while having greater stability and strength and more normal glenoid vault strain. Study Design: Controlled laboratory study. Methods: Sixteen shoulder specimens (8 pairs) were tested by loading the glenohumeral joint with the glenoid intact, following creation of a 25% anterior bone defect, and after random assignment to the Classic or Congruent-Arc Latarjet techniques. Specimens were mounted to a testing apparatus that allowed concentric, centralized loading and loading 30° anterior on the glenoid rim. Cyclic loading (100 cycles at 1 Hz) was applied with a staircase protocol (50, 100, 150, and 200 N). Graft interface displacement and glenoid load transfer, quantified in terms of strain, were recorded during loading. Contact was quantified during 50-N loading using a thin pressure sensor. After cyclic loading, specimens were loaded to failure, defined as 5 mm of graft interface displacement. Results: The 30° loading ≥100 N resulted in significantly greater graft displacement (P < .004) in the Congruent-Arc group as compared with the Classic (mean displacement range, 0.9-2.6 vs 0.1-0.5 mm, respectively). Failure testing yielded a significantly (P = .010) greater ultimate strength for the Classic (557 N) as compared with the Congruent-Arc (392 N). Load-transfer measurements demonstrated that neither technique’s glenoid vault strain values significantly differed from intact (P ≥ .076). Both techniques resulted in contact areas significantly less than intact (P < .035); however, the Congruent-Arc trended toward better contact characteristics (P = .074). Conclusion: The Congruent-Arc results in significantly poorer fixation stability as compared with the Classic technique but did more closely reproduce intact joint contact, which may yield more favorable long-term outcomes. Clinical Relevance: Care must be taken in balancing the consideration of initial fixation stability and joint contact for the Congruent-Arc and Classic Latarjet, as these factors have opposing implications for each of the 2 reconstructions’ outcomes.

The antineoplastic antibiotic taurolidine promotes lung and liver metastasis in two syngeneic osteosarcoma mouse models and exhibits severe liver toxicity

Osteosarcoma (OS) is the most frequent primary bone tumor. Despite multiagent neoadjuvant chemotherapy, patients with metastatic disease have a poor prognosis. Moreover, currently used chemotherapeutics have severe toxic side effects. Thus, novel agents with improved antimetastatic activity and reduced toxicity are needed. Taurolidine, a broad‐spectrum antimicrobial, has recently been shown to have antineoplastic properties against a variety of tumors and low systemic toxicity. Consequently, we investigated in our study the antineoplastic potential of taurolidine against OS in two different mouse models. Although both OS cell lines, K7M2 and LM8, were sensitive for the compound in vitro, intraperitoneal application of taurolidine failed to inhibit primary tumor growth. Moreover, it enhanced the metastatic load in both models 1.7‐ to 20‐fold and caused severe liver deformations and up to 40% mortality. Thus, systemic toxicity was further investigated in tumor‐free mice histologically, by electron microscopy and by measurements of representative liver enzymes. Taurolidine dose‐dependent fibrous thickening of the liver capsule and adhesions and atrophies of the liver lobes were comparable in healthy and tumor‐bearing mice. Liver toxicity was further indicated by up to eightfold elevated levels of the liver enzymes alanine transaminase, aspartate transaminase and GLDH in the circulation. Ultrastructural analysis of affected liver tissue showed swollen mitochondria with cristolysis and numerous lipid vacuoles in the cytoplasm of hepatocytes. The findings of our study question the applicability of taurolidine for OS treatment and may suggest the need for caution regarding the widespread clinical use of taurolidine as an antineoplastic agent.

Unacceptable failure of hemiarthroplasty combined with biological glenoid resurfacing in the treatment of glenohumeral arthritis in the young

BACKGROUND Treatment of glenohumeral osteoarthritis in young patients is challenging. Total shoulder arthroplasty reliably addresses pain and dysfunction but compromises glenoid bone stock. Various efforts have been made to avoid a prosthetic glenoid component or to prevent glenoid erosion after hemiarthroplasty. Capsular interposition, meniscal allograft, and more recently, GraftJacket (Wright Medical Technology Inc, Arlington, TN, USA), a human dermal collagen allograft, have been proposed for interposition arthroplasty in young patients with glenohumeral osteoarthritis. METHODS From 2009 to 2010, GraftJacket was used for glenoid resurfacing combined with humeral resurfacing or a stemmed hemiarthroplasty in 6 patients with a mean age of 47 years (34-57 years). Before GraftJacket was available, 5 patients were treated with a meniscal allograft and 6 with capsular interposition arthroplasty. RESULTS At a mean of 16 months (9-22 months) after the GraftJacket was implanted, 5 of the 6 patients were revised to a total shoulder arthroplasty or a reverse total shoulder arthroplasty. The sixth patient was dissatisfied but declined further surgery. The mean relative, preoperative Constant score decreased from 35% (range, 13%-61%) to 31% (range, 15%-43%) at revision or latest follow-up. Of the 5 patients with meniscal allograft, 3 underwent revision at a mean of 22 months (range, 12-40 months), and 4 of the 6 patients with capsular interposition were revised at a mean of 34 months (range, 23-45 months). The mean relative Constant scores preoperatively and at revision or latest follow-up were 44% (range, 19%-68%) and 58% (range, 9%-96%) for the meniscal allograft patients and 47% (range, 38%-62%) and 63% (range, 32%-92%) for the capsular interposition cases. CONCLUSION In our hands, 3 different types of biological resurfacings combined with humeral hemiarthroplasty have an unacceptable early failure rate.

Suture Anchor Fixation of Bony Bankart Fractures Comparison of Single-Point With Double-Point “Suture Bridge” Technique

Background: As an alternative to the standard single-point suture-anchor technique, a suture-bridge technique has been described for the treatment of bony Bankart fractures. There is, however, little evidence supporting one technique over the other. Purpose/Hypothesis: To compare the failure strength, fixation stability, and loading mechanics of the 2 techniques for the fixation of bony Bankart fractures. We hypothesized that use of the double-point suture-bridge technique would result in superior strength and fixation stability because of the increased compression and contact area between the bony fragment and glenoid fracture site. Study Design: Controlled laboratory study. Methods: A total of 16 shoulders (8 pairs) were tested with an intact glenoid, after creation of a 15% bony Bankart fracture, and after fragment fixation using a single-point or suture-bridge technique. Paired specimens were randomly assigned to each technique. Cyclic progressive loading was applied via a materials testing machine to the glenoid concentrically and eccentrically according to a staircase protocol. Failure strength, fragment displacement, glenoid strain load transfer, and contact area were quantified. Results: No significant differences in failure strength were found between the single-point and suture-bridge techniques (mean strength, 74 ± 28 N vs 77 ± 56 N, respectively; P = .91). Additionally, no significant differences were found for glenoid load transfer (P ≥ .318) and glenohumeral joint contact (P = .357) between the 2 techniques. Centralized loading, however, produced significant differences in fragment displacement at 5, 150, and 200 N (P ≤ .045), with the single-point technique permitting greater fragment displacement in all cases (0.06-0.28 mm). Similarly, eccentric loading caused significantly greater fragment displacement with the single-point technique at ≥25 N compared with the suture-bridge technique (mean range, 0.38-0.63 mm vs 0.14-0.19 mm, respectively; .009 ≤ P ≤ .048). Conclusion: Single-point and suture-bridge techniques for the fixation of bony Bankart fragments have equivalent failure strengths and load transfers. The suture-bridge technique does provide statistically greater initial fracture fragment stability; however, the clinical implications of this are presently unknown. Clinical Relevance: This study will aid in the selection of the optimal repair technique for bony Bankart fractures by providing important insights into the quality of initial fixation and ultimate strength.