Collagen shortening. An experimental approach with heat

Arthroscopic algorithm for acute traumatic triangular fibrocartilage complex (TFCC) tears

The triangular fibrocartilage complex (TFCC) is crucial for stability and acts as a shock absorber and load transmitter at the distal radioulnar joint (DRUJ). It is often injured in wrist trauma, particularly in young athletes. Clinical assessment involves patient history, physical examination, and imaging modalities like MRI, with wrist arthroscopy as the gold standard for diagnosing TFCC tears. Multiple classification systems categorize TFCC tears based on location and arthroscopic appearance, guiding treatment decisions. Surgical options are recommended for tears refractory to conservative management or severe tears. Despite numerous arthroscopic treatments available in the literature, this article aims to simplify the approach. It presents the authors' surgical algorithm for managing acute traumatic TFCC tears arthroscopically. The choice of technique depends on the lesion's location, with various options for peripheral and foveal tears. Post-operative rehabilitation is crucial for optimal recovery. This article provides a comprehensive review of acute traumatic TFCC injuries, covering anatomy, classification, assessment, and treatment options. Emphasis is placed on accurate diagnosis and appropriate arthroscopic management through a structured approach.

Suitability of Slaughterhouse-Acquired Pig Eyes as Model Systems for Refractive Ultraviolet and Infrared Femtosecond Laser Research

PURPOSE

To elucidate whether it is feasible to use porcine eyes from scalded, abattoir-acquired animals for refractive femtosecond laser research.

METHODS

An infrared laser (FS 200) and an ultraviolet laser (prototype version) were tested for their applicability on scalded pig eyes. Fifty porcine eyes were divided into two equally-sized groups and assigned to either the infrared or the ultraviolet laser. Both laser groups were comprised of five subgroups of n = 5 eyes each. Group A: non-scalded eyes (negative control); group B: eyes taken from tunnel-scalded animals; group C1: eyes taken from tank-scalded animals without opaque corneal lesion; group C2: eyes taken from animals with opaque corneal lesion; group D: eyes scalded in toto in the laboratory (positive control). In each group the lasers were employed to create a stromal flap. The quality of the laser cuts and the resulting flap beds, as well as of the porcine corneas themselves, was examined by anterior segment optical coherence tomography and scanning electron microscopy.

RESULTS

All scalded specimens exhibited substantial corneal swelling, most pronounced in group C2. After ultraviolet laser application, the tank- and tunnel-scalded samples displayed marked irregularities and an increased degree of surface roughness in the flap beds. After infrared laser application, this was only the case in the tank-scalded specimens.

CONCLUSION

It is not recommended to use eyes taken from scalded pigs for ultraviolet femtosecond laser experiments. For infrared femtosecond lasers, eyes taken from tunnel-scalded animals may represent an acceptable alternative, if non-scalded eyes are not available.

Compressive Strength Characteristics of Long Tubular Bones after Hyperthermal Ablation

Thermoablation is used in the treatment of tumorous bones. However, little is known about the influence such thermal treatment has on the mechanical properties of bone tissue. The purpose of this work was to study the influence of thermal treatment in a range of 60–100 °C (in increments of 10 °C) on the structural properties of pig femurs using an original approach that involved a periosteal arrangement of heating elements providing gradual dry heating of the bone from its periphery to its center. Heating of freshly extracted bone tissue segments was performed ex vivo using surface heaters of a Phoenix-2 local hyperthermia hardware system. Mechanical testing followed the single-axis compression scheme (traverse velocity of 1 mm/min). In the 60–90 °C range of heating, no attributes of reduced structural characteristics were found in the samples subjected to thermoablation in comparison to the control samples taken from symmetric areas of adjacent cylinders of healthy bones and not subjected to heat treatment. The following statistically significant changes were found as a result of compressing the samples to 100 °C after the heat treatment: reduced modulus of elasticity and increased elastic strain (strain-to-failure), mainly due to increases in plastic deformation. This finding may serve as evidence of a critical ex vivo change in the biomechanical behavior of bone tissues at such temperatures. Thus, ex vivo treatment of bone tissue in the thermal range of 60–90 °C may be used in studies of thermoablation efficiency against tumor involvement of bones.

Usability of abattoir-acquired pig eyes for refractive excimer laser research

The purpose of this study was to elucidate, under which conditions abattoir-acquired pig eyes are suitable for refractive excimer laser experiments. Porcine eyes from tunnel-scalded (n = 5) and tank-scalded (n = 10) pigs were compared to unscalded eyes (n = 5) and to eyes scalded in the laboratory (n = 5). The corneal epithelium was removed before an excimer laser was used to perform a − 8.0 D photoablation. Corneal thickness was measured by optical coherence topography before and after photoablation. The ablation depth was determined with a contour measuring station, the morphology of the ablated areas was characterized by scanning electron microscopy and white-light profilometry. The scalded eyes showed an increase in corneal swelling which gained statistical significance in tank-scalded eyes showing a wedge-shaped opaque stromal lesion in the nasal corneal quadrant. A measurable deterioration of photoablation was only found in tank-scalded eyes that exhibited the opaque lesion. Ablated area morphology was smooth and regular in the unscalded and tunnel-scalded eyes. The tank-scalded eyes showed conspicuous wrinkles. While unscalded eyes should always be preferred for excimer laser laboratory experiments, the data suggest that the use of tunnel-scalded eyes may also be acceptable and should be chosen over tank-scalded eyes.

Effect of root canal irrigant (sodium hypochlorite & saline) delivery at different temperatures and durations on pre-load and cyclic-loading surface-strain of anatomically different premolars

AIM

To evaluate the effect of NaOCl (5%) and saline (control) irrigant delivery at different temperatures and durations on pre-load and cyclic-loading tooth-surface-strain (TSS) on anatomically different premolars.

METHODOLOGY

Single-rooted premolars (n = 36), root-canal-prepared in standard manner, were randomly allocated to six irrigation groups: (A1) NaOCl-21 °C; (A2) NaOCl-60 °C; (A3) saline-21 °C then NaOCl-21 °C; (A4) saline-60 °C then NaOCl-21 °C; (A5) saline-21 °C then NaOCl-60 °C; (A6) saline-60 °C then NaOCl-60 °C. A1-2 received nine 10-min irrigation periods (IP) with NaOCl; A3-6 received nine 10-min IP with saline, followed by 9 IP with NaOCl at different temperature combinations. Premolars (n = 56) with single, fused or double roots prepared by standard protocol, were stratified and randomly allocated to: (B1) saline-21 °C; (B2) saline-80 °C; (B3) NaOCl-21 °C; (B4) NaOCl-80 °C. TSS (μє) was recorded pre-irrigation, post-irrigation and pre-load for each IP and during cyclic loading 2 min after each IP, over 30-274 min, using strain-gauges. Generalised linear mixed models were used for analysis.

RESULTS

Baseline TSS in double-rooted premolars was significantly (p=0.001) lower than in single/fused-rooted-premolars; and affected by mesial-wall-thickness (p=0.005). There was significant increase in loading-TSS (μє) after NaOCl-21 °C irrigation (p=0.01) but decrease after NaOCl-60 °C irrigation (p=0.001). TSS also increased significantly (p = 0.005) after Saline-80 °C irrigation. Pre-load "strain-shift" was noted only upon first saline delivery but every-time with NaOCl. Strain-shift negatively influenced loading-TSS after saline or NaOCl irrigation (A3-6) but was only significant for saline-21 °C.

CONCLUSIONS

Tooth anatomy significantly affected its strain characteristics, exhibiting limits within which strain changes occurred. Intra-canal introduction of saline or NaOCl caused non-random strain shifts without loading. Irrigation with NaOCl-21 °C increased loading tooth strain, as did saline-80 °C or NaOCl-80 °C but NaOCl-60 °C decreased it. A "chain-link" model was proposed to explain the findings and tooth biomechanics.

Treatment of snoring disorder with a non-ablactive Er:YAG laser dual mode protocol. An interventional study

Background

Snoring disorder is a common problem among world population. Treatment modalities may involve surgical and non-surgical procedures. As main objective we proposed to evaluate the efficacy of non-ablative Er:YAG laser in the treatment of snoring disorder.

Material and Methods

We performed an interventional study in 30 patients with snoring disorders. Three sessions were performed with Er:YAG laser 2940nm in long pulse mode (2J/cm2) and smooth mode (10-8J/cm2) in oropharynx region. We analyzed the efficacy of this protocol using questionnaires for snoring intensity, snoring related characteristics of quality of life (including the Epworth sleepness scale and OHIP-14), the satisfaction of the patients and existence of adverse effects comparing the results before and after the treatment using Wilcoxon Signed Rank test.

Results

There was a 96.7% satisfaction rate after one month of treatment, and 96.4% after 6 months. A reduction of the severity of snoring from 8±1.9 before the treatment to 1.6±1.1 one month after treatment was observed (p<0.001). Decrease in mean values of Epworth sleepness scale (9.97±5.3 to 6.54±4.3) (p=0.002), and OHIP-14 score (10.9±6.2 to 5.9±5) (p<0.001) were also noted. A significant decrease in the Mallampatti and Friedman classification scores were observed (p=0.001 and p<0.001, respectively). No anesthesia was required, nor adverse effects were observed.

Conclusions

Non-ablative Er:YAG laser treatment is a safe, painless, and can be an effective treatment option to reduce snoring and is well accepted by the patient. However, further controlled studies with longer follow-up are required.

Key words:Er:YAG laser, snoring, sleep disorders, epworth sleepiness scale, OHIP-14.

The effect of nitrogen plasma on the skin and hair follicles: a possible promising future for the treatment of alopecia

Nowadays, there is a great attention to the plasma applications in medicine. Not only does cold atmospheric pressure plasma provide a therapeutic opportunity to control redox-based processes, it is also an innovative method in rejuvenation. Given the current interest in new methods of rejuvenation, we aimed to introduce a novel pulsed nitrogen plasma torch with potential use in rejuvenation. We investigated production of reactive species at different pulse energy by spectroscopy and also measured nitric oxide and O₂ concentration and evaluated the flame temperature. Fifteen Wistar rats were divided into three groups based on the applied energy settings; the skin of the animals was processed with plasma. For quantitative evaluation of dermis, epidermis and hair follicles (to confirm the effects of this technique on rejuvenation), skin biopsies were taken from both unexposed and treated areas. The spectroscopy results showed the presence of nitric oxide in plasma and the concentration was suitable for dermatological applications. A significant increase was observed in epidermal thickness, fibroblast cell proliferation and collagenesis (P < 0.05). Interestingly, plasma led to a temporary increase in the diameter of primary and secondary hair follicles compared to the controls. The results confirmed the positive effects of this pulsed nitrogen plasma torch on rejuvenation and also revealed a new possible aspect of cold plasma; its effect on hair follicles as a promising area in the treatment of alopecia that requires further clinical and molecular studies.

The effect of NaOCl and heat treatment on static and dynamic mechanical properties and chemical changes of dentine

OBJECTIVES

To determine the effect of heat on flexural strength (FS), maximum strain (MS), storage modulus (SM), tan delta (TD) and chemical changes through micro-Raman spectroscopy of dentine exposed to 2.5% NaOCl or saline.

METHOD

ology: Dentine bars were randomly allocated to 8 test groups. Half (groups 2,4,6,8) were treated with NaOCl for 20 min; the rest (groups 1,3,5,7) remained in saline. FS/MS were measured in groups 1-4 (n = 15) (3/4 were also heated to 200 °C & re-hydrated in saline). Micro-Raman spectroscopy was performed on bars from groups 1-4. SM/TD were measured in 5-8: in 5/6 (n = 10), repeated after heating (200 °C), then following re-hydration; in 7/8 (n = 3) after heating to 25-185 °C.

RESULTS

Increase in MS on heat and FS/MS on heat + NaOCl was not significant (P > 0.05). SM increased (P = 0.06) after heat treatment but reduced to initial state after rehydration (P = 0.03). TD did not change (P = 0.4) after heat (200 °C) treatment but rehydration increased it compared with pre-treatment state (P = 0.001). For dentine bars pre-treated with NaOCl, SM did not change (P = 0.6) after heat (200 °C) treatment or rehydration but TD significantly increased (P = 0.02) upon re-hydration compared with pre- (P=0.007), or post- (P = 0.03) heat-treatment states. SM and TD varied between 25-185 °C with no consistent trend amongst the NaOCl pre-treated bars. Micro-Raman only detected chemical changes following NaOCl treatment in the mineral phase.

CONCLUSIONS

Exposure of dentine bars to heat and NaOCl produced only moderate changes to quasi-static but marked changes to viscoelastic properties, which may be explained by chemical alterations.

Endovenous Laser Application

Introduction: Endoluminal vein treatment is a promising minimal invasive treatment option for peoples suffering from varicose veins. The basic mechanism underlying this procedure is to selectively induce heat in the vessel wall with the result of denaturation of proteins and shrinkage of collagen fibers due to energy application. So far energy could be applied either as RF-current, laser light or water steam. The different approaches to deliver such forms of energies are described.

Methods: Investigations on heat dependent vein tissue effects were performed. The degree of shrinkage and wall thickening due to heat induction was calculated. Tensile test on vein tissue were performed. Investigation using the radial emitting laser fibre in the ox-foot-model under reproducible condition were done and wavelengths dependent tissue reaction were explored.

Results: The experiments clearly demonstrate the degree of the shrinkage of length and diameter, the thickening of the vein wall, as well as the decrease of the elasticity of the tissue. The optical irradiation pattern of the radial emitting laser fiber serves for safe and reproducible energy application directly to the vein wall. Using a laser wavelength with high absorption by the tissue water needs reduced irradiation and irradiance compared to wavelengths with less water absorption. Conclusion: An experimental approach to improve laser application for endovenous varicose treatment is described. Laser parameters and treatment parameters were found which are now under clinical testing. The demonstrated tissue effects may help to find further arguments for clinical findings and sensations described by the patients during follow-up.

Heat-induced inflammation and its role in esophageal cancer

Esophageal cancer, the sixth most common cause of death from cancer worldwide, consists of different histological types and displays various patterns of incidence. Esophageal adenocarcinoma and esophageal squamous cell carcinoma are the most prevalent types. As epidemiological studies report that ingesting hot substances is one major risk factor for squamous cell carcinoma, evaluating the effect of this external stress on esophagus cells seems desirable. This specific kind of stress brings about cellular changes and stabilizes them by affecting different cellular features such as genetic stability, membrane integrity and the regulation of signaling pathways. It also causes tissue injury by affecting the extracellular matrix and cell viability. Thus, one of the main consequences of thermal injury is the activation of the immune system, which can result in chronic inflammation. The genetic alteration that has occurred during thermal injury and the consequent reduction in the function of repair systems is further strengthened by chronic inflammation, thereby increasing the probability that mutated cell lines may appear. The molecules that present in this circumstance, such as heat shock proteins, cytokines, chemokines and other inflammatory factors, affect intercellular signaling pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells, signal transducer activator of transcription-3 and hypoxia-inducible factor 1α in supporting the survival and emergence of mutant phenotypes and the consequent malignant progression in altered cell lines. This investigation of these effective factors and their probable role in the tumorigenic path may improve current understanding.

Arthroscopic Electrothermal Collagen Shrinkage for Symptomatic Laxity of the Scapholunate Interosseous Ligament

The medical records, radiographs and operative reports of ten consecutive patients of average age 37 (range 19–67) years with wrist pain secondary to structural disruption of the scapholunate interosseous ligament (Geissler Type 2 injuries) who were treated with wrist arthroscopy and electrothermal collagen shrinkage of the scapholunate interosseous ligament were reviewed. Functional outcomes were assessed using the DASH scoring system at an average follow-up of 28 (range 12–44) months. At latest follow-up, nine patients (90%) were asymptomatic and had returned to their pre-injury functional level. The mean score on the DASH questionnaire was 20 (range 11–48). One patient developed wrist discomfort and mechanical symptoms 7 months postoperatively and required revision surgery. Our preliminary findings suggest that this may be a viable treatment option in the management of patients with symptomatic scapholunate interosseous ligament laxity without complete ligament disruption. Additional study is needed to better understand the role of this treatment modality.

The use of a high-power laser on swine mitral valve chordae tendineae

Worldwide, rheumatic fever remains a significant cause of mitral valve insufficiency. It is responsible for approximately 90 % of early childhood valvular surgeries in Brazil. Elongated or flail chordae are frequently responsible and require surgical correction. The purpose of this study was to analyze and compare the histological tissues of the mitral valve chordae and the mechanical resistance generated by the chordae, both with and without the application of a high-power laser. Twenty normal porcine mitral valve chordae were measured and divided randomly into the following two groups: control group (not subjected to a high-power laser) and laser group (subjected to photonic irradiation). Laser surgery was performed under controlled conditions, using following parameters: λ = 980-nm wavelength, power = 3 W, and energy = 60 J. A mechanical test machine was used in combination with a subsequent histological study to measure chordae tensile properties. A histological analysis demonstrated a typical collagen bundle arrangement in the control group; however, under a particular reached temperature range (48), the collagen bundles assumed different arrangements in the laser group. Significant reductions in the chordae tendineae lengths and changes in their resistance in the laser group were observed, as these chordae exhibited less rigid fibers. The chordae tendineae of normal porcine valves subjected to a high-power laser exhibited its length reduction and less stiffness compared to the control group. A histological analysis of the laser treatment specimens demonstrated differences in collagen bundle spatial organization, following slight changes into tissue temperature.

Randomized controlled trial of arthroscopic electrothermal capsulorrhaphy with Bankart repair and isolated arthroscopic Bankart repair

PURPOSE

Electrothermal arthroscopic capsulorrhaphy (ETAC) was introduced as an adjunct to shoulder stabilization surgery to address capsular laxity in the treatment of traumatic anterior dislocation. No previous RCT has compared arthroscopic Bankart repair with ETAC of the medial glenohumeral ligament and anterior band of the inferior glenohumeral ligament versus undergoing arthroscopic Bankart repair alone. Our hypothesis was that there would be no difference in quality of life between these two groups. Complication/failure rates were also compared.

METHODS

Eighty-eight patients were randomly assigned to receive arthroscopic Bankart repair with (n = 44) or without ETAC (n = 44). Post-operative visits occurred at 3, 6, 12, and 24 months with WOSI, ASES, and Constant scores completed, and rates of dislocation/subluxation were determined.

RESULTS

Data on 74 patients were analysed, with the rest lost to follow-up. There were no differences between groups at any post-surgery time points for WOSI, ASES, or Constant scores (n.s.). Eight patients in the no-ETAC group and 7 in the ETAC group were considered failures (n.s.).

CONCLUSIONS

No benefits in patient-reported outcome or recurrence rates using ETAC were found. Mean WOSI scores 2 years post-surgery were virtually identical for the two groups. ETAC could not be shown to provide benefit or detriment when combined with arthroscopic labral repair for traumatic anterior instability of the shoulder.

LEVEL OF EVIDENCE

II.

The Effects of Radiofrequency or Cryothermal Ablation on Biomechanical Properties of Isolated Human or Swine Cardiac Tissues

Changes in cardiac tissue properties following the application of various ablation modalities may lead to the development of an array of associated complications. The application of either radio frequency (RF) or cryothermal ablations will alter the biomechanical properties of various cardiac tissues in a differential manner; in some cases, this may be attributable to increased incidences of cardiac tamponade, pulmonary vein stenosis, and/or atrial-esophageal fistula. Thus, a greater understanding of the underlying changes in tissue properties induced by ablative therapies will ultimately promote safer and more efficacious procedures. The effects of applied RF or cryothermal energies on the biomechanical properties of the pulmonary vein, left atrial, or right atrial samples (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text {n}=369$ \end{document}) were examined from fresh excised porcine (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text {n}=35$ \end{document}) and donated human tissue (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text {n}=11$ \end{document}). RF ablations were found to reduce the tensile strength of the porcine cardiac specimens (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text {p}<0.05$ \end{document}), and a similar trend was noted for human samples. Cryoablations did not have a significant impact on the tissue properties compared with the untreated tissue specimens. Locational and species differences were also observed in this experimental paradigm (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text {p}<0.001)$ \end{document}. Incorporating these findings into cardiac device design and computational modeling should aid to reduce the risks of complications associated with tissue property changes resulting from cardiac ablative procedures.

Which is the best method of sterilization for recycled bone autograft in limb salvage surgery: a radiological, biomechanical and histopathological study in rabbit

Background

Limb salvage surgery is a treatment of choice for sarcomas of the extremities. One of the options in skeletal reconstruction after tumour resection is by using a recycled bone autograft. The present accepted methods of recycling bone autografts include autoclaving, pasteurization and irradiation. At the moment there is lack of studies that compare the effectiveness of various sterilization methods used for recycling bone autografts and their effects in terms of bone incorporation. This study was performed to determine the effects of different methods of sterilization on bone autografts in rabbit by radiological, biomechanical and histopathological evaluations.

Methods

Fresh rabbit cortical bone is harvested from the tibial diaphysis and sterilized extracorporeally by pasteurization (n = 6), autoclaving (n = 6), irradiation (n = 6) and normal saline as control group (n = 6). The cortical bones were immediately reimplanted after the sterilization process. The subsequent process of graft incorporation was examined over a period of 12 weeks by serial radiographs, biomechanical and histopathological evaluations. Statistical analysis (ANOVA) was performed on these results. Significance level (α) and power (β) were set to 0.05 and 0.90, respectively.

Results

Radiographic analysis showed that irradiation group has higher score in bony union compared to other sterilization groups (p = 0.041). ANOVA analysis of ‘failure stress’, ‘modulus’ and ‘strain to failure’ demonstrated no significant differences (p = 0.389) between treated and untreated specimens under mechanical loading. In macroscopic histopathological analysis, the irradiated group has the highest percentage of bony union (91.7 percent). However in microscopic analysis of union, the pasteurization group has significantly higher score (p = 0.041) in callus formation, osteocytes percentage and bone marrow cellularity at the end of the study indicating good union potential.

Conclusions

This experimental study shown that both irradiation and pasteurization techniques have more favourable outcome in terms of bony union based on radiographic and histopathological evaluations. Autoclaving has the worst outcome. These results indicate that extracorporeal irradiation or pasteurization of bone autografts, are viable option for recycling bone autografts. However, pasteurization has the best overall outcomes because of its osteocytes preservation and bone marrow cellularity.

Temperature in and around the scapholunate ligament during radiofrequency shrinkage: a cadaver study

PURPOSE

To investigate whether applied radiofrequency energy (RFE) for shrinkage of the scapholunate interosseus ligament reaches temperatures required for ligament shrinkage while leaving adjacent structures unaffected.

METHODS

Standard wrist arthroscopy was performed on 7 pairs of cadaveric limbs with continuous saline irrigation and gravity-assisted outflow through an 18-gauge needle. We subjected 14 scapholunate ligaments to treatment with monopolar (n = 7) or bipolar (n = 7) RFE for ligament shrinkage. Temperature was recorded simultaneously inside the dorsal part of the scapholunate interosseus ligament at a depth of 0.9 ± 0.1 mm and at 6 other sites in and around the wrist because thermal shrinkage starts at 60°C to 65°C.

RESULTS

We observed an increase in temperature corresponding to the time of energy application. The highest measured peak temperatures at the scapholunate ligament were 43°C (monopolar) and 32°C (bipolar). Mean temperatures at 30 seconds of application were 29°C ± 7°C (monopolar) and 28°C ± 3°C (bipolar).

CONCLUSIONS

Temperatures sufficiently high to induce ligament shrinkage were not reached with either monopolar or bipolar RFE. We did not monitor temperature levels responsible for damage on adjacent cartilage or immediately adjacent capsular tissue in this setting.

CLINICAL RELEVANCE

This study suggests that RFE for capsular shrinkage in the wrist is safe but ineffective.

Effect of autoclave devitalization on autograft incorporation and bone morphogenetic protein of tibia in Sprague-Dawley rats

Background: Heating process with autoclave is one of limb salvage modalities that are widely used. but the results are not satisfying, due to mechanical bone fragility. However, considering this treatment modality is widely accepted in terms of financial, religion and sociocultural aspects, we conducted a on study rats treated with resection and reconstruction with autoclave heating method to assess bone healing by sequential radiology, histopathologic osteoblasts count, and bone morphogenetic protein (BMP).Methods: Thirty six Sprague-Dawley rats were divided into two groups with one group being the autoclave group and others served as control group. In both groups, the tibial diaphysis was extracted en bloc for 7 mm. All groups were kept for 8 weeks and treated under the same condition except the autoclave group, where the extracted bones were put into autoclave at 134°C for 15 minutes and refixed again with k-wire. We performed radiological examination at 5th and 8th week using Lane and Sandhu radiological score. After extraction, the tibial bones were inspected for histological pattern using Salked modified score, osteoblast quantity counting and BMP-2 values.Results: There were statistically significant diffences between control and autoclave group on radiological score at 5th (5.12 ± 1.6 g vs 3.21 ± 2.42, p = 0.023) and 8th week (6.06 ± 1.71 vs 4.29 ± 2.53, p = 0.040), histological score between groups (6.06 ± 1.14 vs 4.14 ± 1.99, p = 0.005), osteoblast count (p < 0.001), and BMP-2 expression,  respectively.Conclusion: Autoclave recycling autograft lowered the speed of graft incorporation and BMP-2 expression. Therefore, autoclave recycling autograft as a method of limb salvage surgery must be reevaluated and not considered to be applied for treatment in bone malignancy.  

Temperature profiles of 980- and 1,470-nm endovenous laser ablation, endovenous radiofrequency ablation and endovenous steam ablation

Endovenous thermal ablation (EVTA) techniques are very effective for the treatment of varicose veins, but their exact working mechanism is still not well documented. The lack of knowledge of mechanistic properties has led to a variety of EVTA protocols and a commercially driven dissemination of new or modified techniques without robust scientific evidence. The aim of this study is to compare temperature profiles of 980-and 1,470-nm endovenous laser ablation (EVLA), segmental radiofrequency ablation (RFA), and endovenous steam ablation (EVSA). In an experimental setting, temperature measurements were performed using thermocouples; raw potato was used to mimic a vein wall. Two laser wavelengths (980 and 1,470 nm) were used with tulip-tip fibers and 1,470 nm also with a radial-emitting fiber. Different powers and pullback speeds were used to achieve fluences of 30, 60, and 90 J/cm. For segmental RFA, 1 cycle of 20 s was analyzed. EVSA was performed with two and three pulses of steam per centimeter. Maximum temperature increase, time span of relevant temperature increase, and area under the curve of the time of relevant temperature increase were measured. In all EVLA settings, temperatures increased and decreased rapidly. High fluence is associated with significantly higher temperatures and increased time span of temperature rise. Temperature profiles of 980- and 1,470-nm EVLA with tulip-tip fibers did not differ significantly. Radial EVLA showed significantly higher maximum temperatures than tulip-tip EVLA. EVSA resulted in mild peak temperatures for longer durations than EVLA. Maximum temperatures with three pulses per centimeter were significantly higher than with two pulses. RFA temperature rises were relatively mild, resulting in a plateau-shaped temperature profile, similar to EVSA. Temperature increase during EVLA is fast with a high-peak temperature for a short time, where EVSA and RFA have longer plateau phases and lower maximum temperatures.

Endovenous Laser Application

Introduction: Endovenous laser ablation is becoming a common procedure in clinical routine. Although technical improvements and certain laser parameters are available there is demand to improve the situation by developing feedback-systems, thus getting online information for the clinical outcome and preventing for under- and over-treatment.

Methods: By means of Monte Carlo simulation the potential of detecting signals due to heat induced shrinkage of the vessel was investigated. Remission spectra of native and coagulated vein tissue were compared to identify potential parameters for signalling the physiological change of the tissue due to the heating process. A miniaturized temperature sensor was developed for intraluminal measurements during laser energy application.

Results: Monte Carlo simulation shows that the detection of remitted light from the vessels wall is possible for small vessel calibres of less than 6 mm in diameter. Remission spectra of native compared to coagulated vein tissue differ. While native tissue relates more to the content of deoxy-hemoglobin, the spectra of coagulated tissue relates more to the oxy-hemoglobin state. Based on the principle of temperature dependent fluorescence emission a miniaturized sensor was developed which can be used in the light field of radial emitting fibres.

Conclusion: Several optical changes for online-monitoring of signals during endovenous laser ablation showed potential to serve as feedback mechanism. Up to now, only the measurement of the endoluminal temperature could be realized. Further investigations are needed to find suitable technical realization to prevent for under- or overheating during endovenous laser ablation.

Management of ear lobule keloids using 980-nm diode laser

The objective of the study was to evaluate the 980-nm diode laser in conjunction with corticosteroids in the treatment of ear lobule keloids. Several methods have been described for the treatment of keloid scars, but none of them have been 100% successful. Advances in laser techniques have enabled surgeons to define the most appropriate lasers for use in the treatment of different scar types. The diode laser pulses are delivered interstitially in a single repeated mode in non-overlapping sites using a bare optical fiber, followed by intralesional triamcinolone acetonide injection. The number of sessions varies between two to five for the management of more than 75% of keloid size, with a total success rate of 75% and no recurrence in the follow-up of 12 months. The technique used proved to be effective in the treatment of ear lobule keloids.

Adoption of new technology in sports medicine: case studies of the Gore-Tex prosthetic ligament and of thermal capsulorrhaphy

Evaluation of new technology in sports medicine is supposed to promote improvements in the care of patients. It is also supposed to prohibit technology that can harm patients. This evaluation process is not perfect and at times can promote technology that not only does not help patients but may harm them. Two examples of new sports medicine technology that were widely adopted but eventually abandoned are thermal capsulorrhaphy for treatment of shoulder instability and the Gore-Tex prosthetic ligament (W. L. Gore & Associates, Flagstaff, AZ) for patients with anterior cruciate ligament deficiency. On analysis of the quick adoption of these 2 failed procedures, certain recommendations are apparent for improvement of the evaluation process. There must be a sound rationale behind any new technology, basic science research into the theory of the medical technology, and demonstrated improvements in animal models and clinical studies that are prospective cohort studies or randomized controlled trials, and finally, there must be careful follow-up and postmarket surveillance.

Which is the best method of sterilization of tumour bone for reimplantation? A biomechanical and histopathological study

Introduction

Sterilization and re-usage of tumour bone for reconstruction after tumour resection is now gaining popularity in the East. This recycle tumour bone needs to be sterilized in order to eradicate the tumour cells before re-implantation for limb salvage procedures. The effect of some of these treatments on the integrity and sterility of the bone after treatment has been published but there has yet been a direct comparison between the various methods of sterilization to determine the one method that gives the best tumour kill without compromising the bone's structural integrity.

Method

This study was performed to evaluate the effect of several sterilization methods on the mechanical behavior of human cortical bone graft and histopathology evaluation of tumour bone samples after being processed with 4 different methods of sterilization. Fresh human cortical tumour bone is harvested from the diaphyseal region of the tumour bone were sterilized by autoclave (n =10); boiling (n =10); pasteurization (n =10); and irradiation (n =10). There were also 10 control specimens that did not receive any form of sterilization treatment. The biomechanical test conducted were stress to failure, modulus and strain to failure, which were determined from axial compression testing. Statistical analysis (ANOVA) was performed on these results. Significance level (α) and power (β) were set to 0.05 and 0.90, respectively.

Results

ANOVA analysis of 'failure stress', 'modulus' and 'strain to failure' demonstrated significant differences (p < 0.05) between treated cortical bone and untreated specimens under mechanical loading.

'Stress to failure' was significantly reduced in boiled, autoclaved and irradiated cortical bone samples (p < 0.05). 'Modulus' detected significant differences in the boiled, autoclaved and pasteurization specimens compared to controls (p < 0.05). 'Strain to failure' was reduced by irradiation (p < 0.05) but not by the other three methods of treatments.

Histopathology study revealed no viable tumour cell in any of four types of treatment group compared to the untreated control group.

Conclusions

Sterilization of cortical bone sample by pasteurization and to a lesser extent, irradiation does not significantly alter the mechanical properties when compared with untreated samples. Mechanical properties degrade with the use of high temperature for sterilization (boiling). All methods of sterilization gave rise to 100 percent tumour kill.

Acute Recovery of Patellar Tendon From Heat-Induced Shrinkage and Its Inhibition by Cross-Linking

There are two important factors that accompany heat-induced shrinkage of collagenous tissues: mechanical property degradation and partial recovery from the shrunken length (elongation) upon returning to room temperature (defined here as acute recovery). These undesirable factors reduce the efficacy of thermal therapies. We applied chemical cross-linking adjuvant to thermal treatment on New Zealand White rabbit patellar tendon complexes to explore the feasibility of reducing the impact of these undesirable side-effects. Our results have shown that with exposure to 0.5% w/v glutaraldehyde solution during heating, the recovery response of the patellar tendon tissue was decreased, and the mechanical properties of the tissue were significantly improved.

Electrothermal treatment of thumb basal joint instability

PURPOSE

This study examined whether radiofrequency electrothermal treatment of thumb basal joint instability could produce clinical improvement and result in successful functional outcomes for patients.

METHODS

From August 2001 to April 2006, we treated 17 thumbs with symptomatic thumb basal joint instability using arthroscopic electrothermal shrinkage of the volar ligaments and joint capsule with a monopolar radiofrequency probe. The sample included 11 men and 6 women with a mean age of 35.3 years (range, 20 to 60 years). All patients underwent regular clinical follow-up at a mean of 41 months (range, 24 to 80 months).

RESULTS

Pain improved in all thumbs after surgery. Thumb pinch strength significantly improved in all thumbs after surgery (P < .01). All patients were satisfied with the results and returned to their preinjury activities.

CONCLUSIONS

By use of the described method of arthroscopic electrothermal shrinkage of the volar ligaments and joint capsule in patients with symptomatic thumb basal joint instability, most patients had good subjective results and the pinch strength improved significantly in most patients. Of 17 thumbs, 16 had satisfactory subjective and functional stability at a minimum 2 years' follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Mechanical changes induced by thermal stimulation in collagenous tissue

Radiofrequency thermal stimulation is used as a therapeutic procedure for joint laxity, but its thermal effects are still controversial. Although collagen shrinkage may be expected, this conclusion is empirical and not universally accepted. The purpose of this study was to investigate the mechanical response of collagen to thermal stimulation. A longitudinal cut was made in rabbit Achilles tendons previously marked with monofilament sutures. The distance between the sutures was measured before the cut, just after it was made, and after 8 weeks. The results did not show any shrinkage or significant change in tendon resistance to traction 8 weeks after thermal stimulation; however, comparison with the opposite, normal tendon revealed a statistically significant increase in tendon stiffness.

In vivo effects of partial electrothermal shrinkage on mechanical properties of the anterior cruciate ligament in rabbits

BACKGROUND

No studies have been conducted to clarify an in vivo remodeling of the radiofrequency-treated lesion of the anterior cruciate ligament. The purpose was to determine in vivo effects of radiofrequency shrinkage on mechanical properties of the anterior cruciate ligament.

METHODS

Thirty skeletally mature rabbits were used. In each group, radiofrequency energy set at non-ablative levels was applied to the posterolateral bundle of the anterior cruciate ligament with a bipolar radiofrequency generator. All animals were sacrificed at 0, 6, and 12 weeks after surgery, respectively. In each group, 7 and 3 out of the 10 specimens were used for biomechanical and histological evaluations.

FINDINGS

After shrinkage treatment, the anterior-posterior translation of the knee and the length of the posterolateral bundle were significantly reduced immediately after surgery, but that this effect disappeared at 6 weeks. The tensile strength and the tangent modulus of the treated bundle were significantly lower than that of the normal control bundle at each period. In addition, the tensile strength and the tangent modulus measured at 12 weeks were significantly lower than that at 0 week. Histological examination showed granulation-like tissues with numerous plump fibroblasts and inflammatory cells were dominantly found in the midsubstance of the posterolateral bundle at 12 weeks.

INTERPRETATIONS

This result suggested that the anterior cruciate ligament tissue shortened with the radiofrequency treatment is elongated gradually over time. The mechanical properties of the posterolateral bundle of the anterior cruciate ligament reduced by the radiofrequency shrinkage are not restored in vivo, but significantly deteriorated with time.

Inhibitory effect of Hemidesmus indicus and its active principle 2-hydroxy 4-methoxy benzoic acid on ethanol-induced liver injury

The study evaluates the inhibitory activity of ethanolic root extract of Hemidesmus indicus (H. indicus) and its active principle 2-hydroxy 4-methoxy benzoic acid (HMBA) on liver fibrotic markers and characteristics such as collagen content, matrix metalloproteinases (MMPs) 2 and 9 in ethanol-fed rats. Experimental groups were control, H. indicus (500 mg/kg body weight every day during the last 30 days), HMBA (200 microg/kg body weight every day during the last 30 days), alcohol (5 g/kg body weight by intragastric intubation everyday, i.e. throughout the experimental period of 60 days), alcohol plus H. indicus and alcohol plus HMBA. Ethanol administration significantly increased the levels of liver collagen and hydroxy proline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and significantly decreased the solubility of liver collagen and the ascorbic acid content when compared with control rats. On treatment with H. indicus and HMBA the ethanol-fed rats showed significantly reduced levels of liver collagen and hydroxyproline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and enhanced solubility of liver collagen and ascorbic acid levels when compared with untreated ethanol-fed rats. MMPs were extracted from the liver of control, H. indicus-treated, HMBA-treated, ethanol-administered, ethanol with H. indicus-coadministered and ethanol with HMBA-coadministered rats. The inhibition was analyzed by gelatin zymography and the percentage of expression was determined by a gel documentation system. The activities of MMPs 2 and 9 were significantly increased in ethanol-supplemented rats. Cotreatment of H. indicus/HMBA with ethanol showed significantly decreased activities of these enzymes when compared with those of the untreated rats. H. indicus/HMBA alone treatment showed no such significant alterations. Thus, our present study reveals the strong inhibitory activity of H. indicus and HMBA on the quantitative and qualitative properties of hepatic collagen and also MMPs involved in the extracellular matrix degradation during ethanol intoxication.

Electrothermal arthroscopic shoulder capsulorrhaphy: a minimum 2-year follow-up

BACKGROUND

Few studies have documented the outcomes of thermal capsulorrhaphy for shoulder instability.

PURPOSE

To examine prospective evaluate outcomes of the first 100 patients with glenohumeral instability treated with thermal capsulorrhaphy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 1997 and 1999, 85 of 100 patients treated with thermal capsulorrhaphy for glenohumeral instability were available for review at 2-year minimum follow-up (average, 4 years). Fifty-one patients suffered from anterior instability; 24 had an associated Bankart lesion. Ten patients demonstrated posterior instability; 1 had an associated reverse Bankart lesion. Seventeen patients had multidirectional instability; 8 had an associated Bankart lesion. Seven patients demonstrated anterior and posterior instability without an inferior component; 2 had an associated Bankart lesion. Failures were defined as shoulders requiring revision stabilization (14) or with recurrent instability (18), recalcitrant pain (3), or stiffness (2).

RESULTS

Forty-eight of 85 procedures were successful, and 37 of 85 failed. For patients with anterior instability plus a Bankart lesion, 7 of 24 (26%) had failed results. For those with anterior instability without a Bankart lesion, 10 of 27 (33%) had failed results. The failure rates for posterior, multidirectional instability, and anteroposterior were 60% (6/10), 59% (10/17), and 57% (4/7), respectively. Of the 48 successes, mean preoperative American Shoulder and Elbow Surgeons score improved from 71 to 96 postoperatively, and patient satisfaction was 9.1 on a 10-point scale.

CONCLUSION

Because of the high failure rates, we now augment thermal capsulorrhaphy with capsular plication and/or rotator interval closure in cases of posterior and multidirectional instability and have lengthened the initial immobilization period to improve outcomes. Failure rates for thermal capsulorrhaphy, even with labral repairs, are high especially for shoulders with multidirectional instability and posterior instability. When procedures were successful, however, patients were very satisfied with significant improvements in American Shoulder and Elbow Surgeons scores.

Standardisation of Parameters during Endovenous Laser Therapy of Truncal Varicose Veins - Experimental Ex-vivo Study

BACKGROUND

Vein shrinkage is a surrogate marker for successful laser treatment of varicose veins. However, many controversies still remain concerning the best laser parameters to use. The aim of this study was standardisation of intraoperative energy dosages and pull-back rates to achieve optimal clinical results.

DESIGN

Ex-vivo study in surgically removed saphenous trunks.

MATERIAL AND METHODS

Great saphenous veins were removed by Babcock stripping and irradiated with laser energy delivered by a laser diode emitting at 980 nm. In total, 279 vein segments (5 cm long) were treated using powers from 5-15 W. Vein segments were opened longitudinally and the circumference measured in the treated and untreated regions to assess thermal shrinkage.

RESULTS

The greatest shrinkage and minimum number of perforations was achieved using lower or medium power (8 to 12 W) with longer exposure to administer laser energy. The median percentage vein shrinkage was 50% (power 5 W), 45% (8 W), 40% (10 W), 45% (12 W) and 59% (15 W). When a higher power was used (15 W), the perforations were more frequent and carbonisation was marked.

CONCLUSIONS

Our data suggests that similar efficacy with fewer vein perforations may be obtained with low or medium power settings and increased exposure when undertaking laser obliteration of saphenous trunks. This may result in fewer adverse events such as ecchymosis following treatment in patients.

The Evolution and Advancement of Endoscopic Foraminal Surgery: One Surgeon's Experience Incorporating Adjunctive Techologies

Background

Endoscopic spine surgery has evolved gradually through improvements in endoscope design, instrumentation, and surgical techniques. The ability to visualize and treat painful pathology endoscopically through the foramen has opened the door for the diagnosis and treatment of degenerative conditions of the lumbar spine (from T10 to S1). Other endoscopic techniques for treating a painful disc have been focused on a posterior approach and has been compared with micro–lumbar discectomy. These procedures have not been more effective than open microdiscectomy but are less invasive, have less surgical morbidity, and allow for more rapid surgical recovery. Spinal decompression and fusion was the fallback procedure when nonsurgical treatment or discectomy failed to relieve sciatica and back pain. Foraminal endoscopic surgery, however, provides a truly minimally invasive alternative approach to the pathoanatomy of the lumbar spine because it preserves the multifidus muscle, maintains motion, and eliminates or, at worst, delays the need for fusion.

Methods

The following developments helped facilitate the evolution of a transforaminal endoscopic surgery procedure for disc herniations from a foraminal disc decompression, also known as percutaneous endoscopic lumbar discectomy, to a more complete foraminal surgical technique that can address spinal stenosis and spinal instability. This expanded capability gives foraminal endoscopic surgery distinct advantages and flexibility for certain painful degenerative conditions compared with open surgery. Advancement of the technique occurred when needle trajectory and placement was refined to better target each type of herniation with precise needle and cannula positioning directed at the herniation. New instrumentation and inclusion of a biportal technique also facilitated removal of extruded, migrated, and sequestered disc herniations. The further development of foraminoscopes with larger working channels and high speed burrs to remove bone more efficiently, along with recognition of foraminal pathoanatomy in the foramen, led to the identification and treatment of other painful degenerative conditions of the lumbar spine such as failed back surgery syndrome, recurrent disc herniations, lateral foraminal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis.

A summary of the endoscopic techniques currently used and trademarked by the author as the YESS technique include: (1) a published protocol for optimal needle and instrument placement calculated by lines drawn on the skin from the C-arm image; (2) evocative chromodiscography by the operating surgeon with nonionic radiologic contrast and indigo carmine dye to confirm concordant pain production and to stain tissue in contact with the injectate; (3) selective endoscopic discectomy, which targets the removal of loose degenerative nucleus stained differentially by indigo carmine dye; (4) thermal annuloplasty, a visualized radiofrequency thermal modulation of disc and annular defects guided by vital tissue staining; (5) endoscopic foraminoplasty, a decompression of the lateral and subarticular recess, including disc and foraminal degenerative and isthmic spondylolisthesis; (6) visually and radiologically guided exploration of the epidural space; (7) probing the hidden zone of MacNab for normal nerves (and branches of spinal nerves known as furcal nerves) versus anomalous autonomic nerves in the foramen; and (8) a uniportal and biportal technique for inside-out removal of extruded and sequestered nucleus pulposus.

Results

Endoscopic foraminal surgical procedures are not limited to disc decompression. The approaches and techniques allow access to the lumbar spine for treatment of conditions ranging from discogenic pain to failed back surgery syndrome (most commonly caused by residual or recurrent disc herniation and lateral recess stenosis). More than 3000 patients have undergone endoscopic posterolateral surgical exploration and decompression by the author since 1991. The first 80 patients reported formed the basis for expansion of techniques as new instruments and adjunctive therapy methods were added to selective endoscopic discectomy and thermal annuloplasty. New anatomic and pathoanatomic conditions were reported as they were encountered.

Conclusions

New skills will become desirable and necessary for the spine surgeon to keep up with endoscopic technology in spine care. The emphasis is on visualization of painful pathoanatomy and preservation of mobility. A new focus is on nucleus replacement, annular repair, annular reinforcement, biologics, and even transforaminal interbody fusion as the procedure of last resort. The transforaminal surgical approach to the lumbar spine can allow for minimally invasive access without negatively affecting and destabilizing the multifidus muscle.

Estudo das propriedades mecânicas do ligamento cruzado posterior e do ligamento patelar de cadáveres de seres humanos após utilização de radiofreqüência

Este trabalho visou estudar os efeitos da radiofreqüência sobre os ligamentos patelares (LP) e ligamentos cruzados posteriores (LCP) de cadáveres, levando em conta as características de rigidez e deformação máxima. Foram utilizados 11 LCP e 14 LP, sendo feitas as aferições com o aparelho Kratos® K5002 . Foi realizada a termoabrasão das estruturas, com encurtamento obtido entre 15 e 20% do comprimento inicial. Observou-se que essas deformações (encurtamento) não se mantiveram no ensaio pós RF. Conclusão: A radiofreqüência permite o encurtamento do LP e LCP. O encurtamento obtido não se mantém completamente quando os ligamentos são submetidos a cargas tensionais padronizadas neste ensaio biomecânico. O uso de radiofrequência causa redução da rigidez do tecido (LP e LCP).

The inferior glenohumeral ligament: a correlative investigation

The inferior glenohumeral ligament (IGHL) was investigated by correlating the biomechanical properties, biochemical composition, and histologic morphology of its 3 anatomic regions (superior band, anterior axillary pouch, and posterior axillary pouch) in 8 human cadaveric shoulders. The overall biochemical composition of the IGHL appeared similar to other ligaments, with average water content of 80.9 +/- 2.5%, collagen content of 80.0 +/- 9.2%, and crosslinks of 0.715 +/- 0.13 mol/mol collagen. The proteoglycan content was highest in the superior band (2.73 +/- 0.7 mg/g dry weight) and may, in part, explain its viscoelastic behavior. Histologic analysis demonstrated longitudinally organized fiber bundles that were more uniform in the mid-substance but more interwoven and less uniformly oriented near the insertion sites. The superior band had the most pronounced fiber bundle interweaving, while crimping was more evident in the anterior axillary pouch. Elastin was identified in each of the regions. Tensile testing demonstrated a trend toward higher ultimate tensile stress (16.9 +/- 7.9 MPa) and tensile modulus (130.3 +/- 47.9 MPa) in the superior band compared to the axillary pouch. The mean ultimate tensile strain of the IGHL was 16.8 +/- 4.6%. These complex IGHL properties may help to explain its unique functions in stabilizing the shoulder in different arm positions and at different rates of loading, including the failure patterns seen clinically, as in Bankart lesions (insertion site) versus capsular stretching (ligament substance).

Thermal capsulorrhaphy for the treatment of shoulder instability

Thermal capsulorrhaphy has been used to treat many different types of shoulder instability, including multidirectional instability, unidirectional instability, and microinstability in overhead-throwing athletes. A device that delivers laser energy or radiofrequency energy to the capsule tissue causes the collagen to denature and the capsule to shrink. The optimal temperature to achieve the most shrinkage without causing necrosis of the tissue is between 65 degrees and 75 degrees centigrade. This treatment causes a significant decrease in mechanical stiffness for the first 2 weeks, and then, after the tissue undergoes active cellular repair from the surrounding uninjured tissue, the mechanical properties return to near normal by 12 weeks. If the thermal energy is applied in a grid pattern, then the tissue heals with more stiffness by 6 weeks. Clinical studies on thermal capsulorrhaphy for the treatment of multidirectional instability have shown a high rate of recurrent instability (12%-64%). The clinical studies on unidirectional instability showed much better recurrence rates (4%-25%), but because most of the patients also underwent concomitant Bankart repairs and superior labral anterior posterior lesion repairs, the efficacy of the thermal treatment cannot be ascertained. A randomized controlled trial would be needed to assess whether instability with Bankart lesions requires augmentation with thermal capsulorrhaphy. For the patients with microinstability who are overhead-throwing athletes, thermal capsulorrhaphy has shown varying results from a 97% rate of return to sports to a 62% rate of return to sports. Complications of this technique include temporary nerve injuries that usually involve the sensory branch of the axillary nerve and thermal necrosis of the capsule, which is rare.

Monopolar radiofrequency electrothermal shrinkage of the scapholunate ligament

PURPOSE

This study examined whether radiofrequency electrothermal shrinkage has a role in the treatment of patients with symptomatic dynamic and predynamic scapholunate (SL) instability without advanced degenerative changes.

METHODS

From January 1999 to July 2001, 19 wrists with laxity of the SL ligament, but with symptomatic instability, were treated with arthroscopic electrothermal shrinkage of the SL ligament using a monopolar radiofrequency probe. Before surgery, all patients underwent wrist arthroscopy to confirm the diagnosis and exclude arthritis. The sample included 16 men and 3 women with an average age of 23.3 years (range, 18 to 27 years). The average time from injury to operation was 17.2 months (range, 14 to 28 months). All patients underwent follow-up at our clinic regularly for an average of 28.1 months (range, 24 to 34 months).

RESULTS

All 19 patients had attenuation or laxity of the continuity SL ligament in the radiocarpal joint. Modified Mayo wrist scores revealed the following functionality: the total arc of wrist motion in the flexion-extension plane loss averaged 5.1 degrees (P > .01). Grip force improved significantly, with 14.7% improvement of that on the normal side (P < .01). The Wilcoxon signed-rank test was used to compare the results: the postoperative scores were significantly better than the preoperative scores (P < .01). Fifteen patients (79%) were fully satisfied with the results and returned to their preinjury activity. Four patients (21%) had recurrent laxity of the SL joint.

CONCLUSIONS

Electrothermal shrinkage of the SL ligament in patients with symptomatic, predynamic and dynamic SL instability had a 79% success rate at a minimum of 2 years' follow-up.

LEVEL OF EVIDENCE

Level IV, case series.