Effect of radiofrequency use on hip arthroscopy irrigation fluid temperature

Hip Arthroscopy Versus Physical Therapy for the Treatment of Symptomatic Acetabular Labral Tears in Patients Older Than 40 Years: 24-Month Results From a Randomized Controlled Trial

BACKGROUND

The indications for hip arthroscopy in patients aged ≥40 years remain controversial, as observational studies have suggested that advanced age portends poor functional outcomes, poor durability of improvement, and high rates of conversion to total hip arthroplasty.

PURPOSE

To compare hip arthroscopy versus nonoperative management for symptomatic labral tears in patients aged ≥40 years with limited radiographic osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This single-surgeon, parallel randomized controlled trial included patients aged ≥40 years with limited osteoarthritis (Tönnis grades 0-2) who were randomized 1:1 to arthroscopic surgery with postoperative physical therapy (SPT) or physical therapy alone (PTA). Patients who received PTA and achieved unsatisfactory improvement were permitted to cross over to SPT after completing ≥14 weeks of physical therapy (CO). The primary outcomes were the International Hip Outcome Tool-33 score and modified Harris Hip Score at 24 months after surgery, and secondary outcomes included other patient-reported outcome measures and the visual analog scale for pain. The primary analysis was performed on an intention-to-treat basis using linear mixed-effects models. Sensitivity analyses included modified as-treated and treatment-failure analyses.

RESULTS

A total of 97 patients were included, with 52 (53.6%) patients in the SPT group and 45 (46.4%) patients in the PTA group. Of the patients who underwent PTA, 32 (71.1%) patients crossed over to arthroscopy at a mean of 5.10 months (SD, 3.3 months) after physical therapy initiation. In both intention-to-treat and modified as-treated analyses, the SPT group displayed superior mean patient-reported outcome measure and pain scores across the study period for nearly all metrics relative to the PTA group. In the treatment-failure analysis, the SPT and CO groups showed greater improvement across all metrics compared with PTA; however, post hoc analyses revealed no significant differences in improvement between the SPT and CO groups. No significant differences were observed between groups in rates of total hip arthroplasty conversion.

CONCLUSION

In patients ≥40 years of age with limited osteoarthritis, hip arthroscopy with postoperative physical therapy led to better outcomes than PTA at a 24-month follow-up. However, additional preoperative physical therapy did not compromise surgical outcomes and allowed some patients to avoid surgery. When surgery is indicated, age ≥40 years should not be considered an independent contraindication to arthroscopic acetabular labral repair.

REGISTRATION

NCT03909178 (ClinicalTrials.gov identifier).

Association Between Severity of Chondrolabral Junction Breakdown and Functional Outcomes After Hip Arthroscopy for Acetabular Labral Tears

BACKGROUND

Despite focus on surgical preservation of the chondrolabral junction (CLJ), the transition zone between the acetabular cartilage and labrum, the association between severity of CLJ breakdown and functional outcomes after hip arthroscopy remains unexplored.

PURPOSE

To assess the influence of CLJ breakdown on patient-reported outcome measures (PROMs) at a 24-month follow-up after hip arthroscopy for symptomatic labral tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of prospectively collected data was conducted to identify patients ≥18 years of age with a minimum 24-month follow-up who underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to femoroacetabular impingement. The Beck classification of transition zone cartilage was used to grade CLJ damage; patients with grades 0 to 2 were stratified into the mild CLJ damage cohort, and those with grades 3 and 4 were stratified into the severe CLJ damage cohort. PROMs were collected at baseline and at 3, 6, 12 months, and annually thereafter postoperatively. Linear mixed-effects models were used to compare PROMs. Rates of achieving clinically meaningful thresholds and subsequent surgery rates were also compared.

RESULTS

In total, 198 patients met the inclusion criteria, with a mean follow-up of 3.54 ± 1.26 years. A total of 95 patients with severe CLJ damage (mean age, 34.9 ± 10.5 years) were compared with 103 patients with mild CLJ damage (mean age, 38.2 ± 11.9 years). Hip Outcome Score-Activities of Daily Living (HOS-ADL), Non-Arthritic Hip Score (NAHS), and visual analog score for pain were inferior in the severe CLJ group at enrollment and all follow-up time points (P≤ .05). However, patients with severe CLJ breakdown exhibited greater improvements in HOS-ADL and NAHS at the 24-month follow-up and achieved clinically meaningful thresholds at equivalent rates to patients with mild CLJ breakdown. Subsequent surgery rates were 6.8% and 12.6% in patients with mild versus severe CLJ damage, respectively (P = .250).

CONCLUSION

Severe CLJ breakdown is associated with increased pain and decreased functional level preoperatively and up to 24 months after hip arthroscopy. Despite this, patients with severe CLJ breakdown experienced greater improvements in functional outcomes at a 24-month follow-up and achieved clinical thresholds at similar rates to patients with mild CLJ damage. Thus, while worse baseline pain and functional levels may indicate severe CLJ breakdown, these patients still benefit substantially from hip arthroscopy.

Preoperative Paralabral Cysts Predict More Significant Chondral Damage but Not 2-Year Functional Outcomes Following Arthroscopic Labral Repair

PURPOSE

To investigate whether paralabral cysts identified incidentally on preoperative magnetic resonance imaging/arthrography predict 2-year functional outcomes after arthroscopic acetabular labral repair.

METHODS

Prospectively collected data for patients undergoing primary hip arthroscopy by a single surgeon from 2014 to 2020 were retrospectively reviewed. Included patients were ≥18 years and completed baseline patient-reported outcome measures (PROMs) with additional follow-up at 3, 6, 12, and 24 months. Exclusion criteria were labral debridement, hip dysplasia, advanced hip osteoarthritis (Tönnis > 1), or previous ipsilateral hip surgery. Patients were stratified based on the presence of paralabral cysts identified on magnetic resonance imaging/arthrography. Primary outcomes were International Hip Outcome Tool and modified Harris Hip Score. Secondary outcomes included other PROMs and the visual analog pain scale. Outcomes were compared between cohorts using linear mixed-effects models and Fisher's exact tests. Sensitivity analyses accounted for preoperative PROMs, nonlinear improvement trajectories, and relevant baseline characteristics.

RESULTS

Of the 182 included hips (47.8% female; mean ± standard deviation age, 36.9 ± 11.4), 30 (16.4%) had paralabral cysts. During the 2-year study period, there were no significant differences between patients with and without paralabral cysts in terms of International Hip Outcome Tool scores (weighted difference = 1.60; 95% confidence interval [CI], -5.09, 8.28; P = .64), modified Harris Hip Scores (weighted difference = 0.56; 95% CI, -4.16, 5.28; P = .82), or any secondary outcomes (except for HOS-Sports Subscale at 3 months [mean difference = -11.85; 95% CI, -22.85, -0.84; P = .035]). Furthermore, there were no significant differences in clinically meaningful outcomes (P > .05 for all), revision rates (P > .99), or conversion to total hip arthroplasty between cohorts (P > .99). These results held across all sensitivity analyses.

CONCLUSIONS

Although preoperative paralabral cysts were associated with worse cam impingement and more severe chondral damage observed intraoperatively, they did not predict 2-year functional outcomes or clinically meaningful improvements, suggesting that incidentally discovered paralabral cysts are not a contraindication for arthroscopic labral repair.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Association Between Chondrolabral Junction Breakdown and Conversion to Total Hip Arthroplasty After Hip Arthroscopy for Symptomatic Labral Tears: Minimum 8-Year Follow-up

BACKGROUND

Arthroscopic treatment of femoroacetabular impingement (FAI) and symptomatic labral tears confers short- to midterm benefits, yet further long-term evidence is needed. Moreover, despite the physiological and biomechanical significance of the chondrolabral junction (CLJ), the clinical implications of damage to this transition zone remain understudied.

PURPOSE

To (1) report minimum 8-year survivorship and patient-reported outcome measures after hip arthroscopy for FAI and (2) characterize associations between outcomes and patient characteristics (age, body mass index, sex), pathological parameters (Tönnis angle, alpha angle, type of FAI, CLJ breakdown), and procedures performed (labral management, FAI treatment, microfracture).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This retrospective cohort study included patients who underwent primary hip arthroscopy for symptomatic labral tears secondary to FAI by a single surgeon between 2002 and 2013. All patients were ≥18 years of age with minimum 8-year follow-up and available preoperative radiographs. The primary outcome was conversion to total hip arthroplasty (THA), and secondary outcomes included revision arthroscopy, patient-reported outcome measures, and patient satisfaction. CLJ breakdown was assessed using the Beck classification. Kaplan-Meier estimates and weighted Cox regression were used to estimate 10-year survivorship (no conversion to THA) and identify risk factors associated with THA conversion.

RESULTS

In this study of 174 hips (50.6% female; mean age, 37.8 ± 11.2 years) with mean follow-up of 11.1 ± 2.5 years, the 10-year survivorship rate was 81.6% (95% CI, 75.9%-87.7%). Conversion to THA occurred at a mean 4.7 ± 3.8 years postoperatively. Unadjusted analyses revealed several variables significantly associated with THA conversion, including older age; higher body mass index; higher Tönnis grade; labral debridement; and advanced breakdown of the CLJ, labrum, or articular cartilage. Survivorship at 10 years was inferior in patients exhibiting severe (43.6%; 95% CI, 31.9%-59.7%) versus mild (97.9%; 95% CI, 95.1%-100%) breakdown of the CLJ (P < .001). Multivariable analysis identified worsening CLJ breakdown (weighted hazard ratio per 1-unit increase, 6.41; 95% CI, 3.11-13.24), older age (1.09; 95% CI, 1.04-1.14), and higher Tönnis grade (4.59; 95% CI, 2.13-9.90) as independent negative prognosticators (P < .001 for all).

CONCLUSION

Although most patients achieved favorable minimum 8-year outcomes, several pre- and intraoperative factors were associated with THA conversion; of these, worse CLJ breakdown, higher Tönnis grade, and older age were the strongest predictors.

Outcomes of Hip Arthroscopy in the Setting of Concomitant Symptomatic Lumbosacral Spine Pathology: A Matched Control Study With Minimum 24-Month Follow-up

BACKGROUND

The overlapping biomechanical relationship between the lumbosacral spine and pelvis poses unique challenges to patients with concomitant pathologies limiting spinopelvic range of motion.

PURPOSE

To assess the influence of concomitant, symptomatic lumbosacral spine pathology on patient-reported outcome measures (PROMs) after hip arthroscopy for the treatment of femoroacetabular impingement (FAI) and symptomatic labral tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective query of prospectively collected data identified patients aged ≥18 years with a minimum 24-month follow-up who underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to FAI. Patients were stratified into cohorts based on the presence (hip-spine [HS]) or absence (matched control [MC]) of symptomatic lumbosacral spine pathology. Inclusion within the HS cohort required confirmation of lower back pain/symptoms on preoperative surveys plus a diagnosis of lumbosacral spine pathology verified by radiology reports and correlating clinical documentation. Patients with previous spine surgery were excluded. PROMs were compared between groups, along with rates of achieving minimal clinically important difference (MCID) thresholds, Patient Acceptable Symptom State (PASS) thresholds, revision arthroscopy, and conversion to total hip arthroplasty (THA).

RESULTS

A total of 70 patients with lumbosacral pathology were coarsened exact matched to 87 control patients without spinal pathology. The HS cohort had preoperative baseline scores that were significantly worse for nearly all PROMs. Follow-ups at 3, 6, 12, and 24 months displayed similar trends, with the HS cohort demonstrating significantly worse scores for most collected outcomes. However, at every time point, HS and MC patients exhibited similar magnitudes of improvement across all PROM and pain metrics. Furthermore, while significantly fewer HS patients achieved PASS for nearly all PROMs at 12- and 24-month follow-ups, MCID thresholds were reached at similar or greater rates across all PROMs relative to the MC cohort. Finally, there were no significant differences in rates of revision or THA between cohorts at maximum available follow-up.

CONCLUSION

After hip arthroscopy to address labral tears in the setting of FAI, patients with symptomatic lumbosacral pathologies and no history of spine surgery were found to exhibit inferior pre- and postoperative PROMs but achieved statistically similar clinical benefit and rates of PROM improvement through 24-month follow-up compared with the MC cohort with isolated hip disease. These findings aid in providing a realistic recovery timeline and evidence that coexisting hip and spine disorders are not a contraindication for arthroscopic hip preservation surgery.

Intra-articular temperature monitoring during radiofrequency ablation in ex-vivo bovine hip joints via Fiber Bragg grating sensors

PURPOSE

Radiofrequency ablation is an increasingly used surgical option for ablation, resection and coagulation of soft tissues in joint arthroscopy. One of the major issues of thermal ablation is the temperature monitoring across the target areas, as cellular mortality is a direct consequence of thermal dosimetry. Temperatures from 45 °C to 50 °C are at risk of damage to chondrocytes. One of the most reliable tools for temperature monitoring is represented by fiber optic sensors, as they allow accurate and real-time temperature measurement via a minimally invasive approach. The aim of this study was to determine, by fiber Bragg grating sensors (FBGs), the safety of radiofrequency ablation in tissue heating applied to ex-vivo bovine hip joints.

METHODS

Ex vivo bovine hips were subjected to radiofrequency ablation, specifically in the acetabular labrum, for a total of two experiments. The WEREWOLF System (Smith + Nephew, Watford, UK) was employed in high operating mode and in a controlled ablation way. One optical fiber embedding seven FBGs was used to record multipoint temperature variations. Each sensor was 1 mm in length with a distance from edge to edge with each other of 2 mm.

RESULTS

The maximum variation was recorded in both the tests by the FBG1 (i.e., the closest one to the electrode tip) and was lower than to 2.8 °C. The other sensors (from FBG2 to FBG7) did not record a significant temperature change throughout the duration of the experiment (maximum up to 0.7 °C for FBG7).

CONCLUSIONS

No significant increase in temperature was observed at any of the seven sites. The sensor nearest to the radiofrequency source exhibited the highest temperature rise, but the variation was only 3 °C. The minimal temperature increase registered at the measurement sites, according to existing literature, is not expected to be cytotoxic. FBGs demonstrate the potential to fulfil the strict requirements for temperature measurements during arthroscopic surgery.

Labral Reconstruction via Capsular Augmentation Maintains Perfusion to the Acetabular Labrum and Locally Transferred Autograft: An in Vivo Laser Doppler Flowmetry Analysis

Background

The purpose of the present study was to examine the effects of arthroscopic labral repair with capsular augmentation on blood flow in vivo with use of laser Doppler flowmetry (LDF) to measure microvascular perfusion of the labrum and autograft tissue.

Methods

The present prospective case series included patients ≥18 years old who underwent arthroscopic acetabular labral repair with capsular augmentation; all procedures were performed by a single surgeon between 2018 and 2022. The LDF probe measured microvascular blood flow flux within 1 mm3 of the surrounding labral and capsular tissue of interest. Mean baseline measurements of flux were compared with readings immediately following capsular elevation and after completing labral augmentation. Blood flux changes were expressed as the percent change from the baseline measurements.

Results

The present study included 41 patients (24 men [58.5%] and 17 women [41.5%]) with a mean age (and standard deviation) of 31.3 ± 8.4 years, a mean BMI of 24.6 ± 3.4 kg/m2, a mean lateral center-edge of angle 35.3° ± 4.9°, a mean Tönnis angle of 5.8° ± 5.8°, and a mean arterial pressure of 93.7 ± 10.9 mm Hg. Following capsular elevation, the mean percent change in capsular blood flow flux was significantly different from baseline (-9.24% [95% confidence interval (CI), -18.1% to -0.04%]; p < 0.001). Following labral augmentation, the mean percent change in labral blood flow flux was significantly different from baseline both medially (-22.3% [95% CI, -32.7% to -11.9%]; p < 0.001) and laterally (-32.5% [95% CI, -41.5% to -23.6%]; p = 0.041). There was no significant difference between the changes in medial and lateral perfusion following repair (p = 0.136).

Conclusions

Labral repair with capsular augmentation sustains a reduced blood flow to the native labrum and capsular tissue at the time of fixation. The biological importance of this reduction is unknown, but these findings may serve as a benchmark for other labral preservation techniques and support future correlations with clinical outcomes.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Thermal Dynamics of a Novel Radio-Frequency Device for Endoscopic Spine Surgery: An Experimental Model

STUDY DESIGN

Experimental study.

OBJECTIVE

In this study, the ambient temperature of a radiofrequency (RF) electrode tip was compared and analyzed in terms of products, mode, flow quantity, and flow rate.

SUMMARY OF BACKGROUND DATA

Endoscopic spine surgery is a widely used operation for degenerative lumbar stenosis and herniated lumbar disc. To perform endoscopic spine surgery, dedicated instruments like a RF generator and electrode are essential.

METHODS

An evaluation system capable of measuring temperature under equal conditions at a certain distance from the electrode tip was manufactured. The distance between the electrode tip and the temperature sensor was set to 1, 5, and 10 mm. The flow quantities of 0, 50, 100, and 150 mL/min and the flow rates of 0, 0.20, 0.53, and 0.80 m/s were compared and statistically analyzed.

RESULTS

The temperatures measured in the experiments conducted on the four combinations of RF device showed similar values, and showed differences according to the characteristics of each mode of the RF. As the distance between the electrode tip and the temperature sensor increased, the temperature decreased, and as flow quantity or flow rate increased, the temperature decreased. The maximum temperatures differed significantly according to flow quantity, between flow quantities of 0 and 100 mL/min (P  = 0.03) and between 0 and 150 mL/min (P ≤ 0.01). The maximum temperatures also differed significantly between the flow rate of 0 m/s, and the flow rates of 0.20, 0.53, and 0.80 m/s, with P ≤ 0.01 in all three comparisons.

CONCLUSION

This is the first study in which we made a customized RF temperature evaluation system and verified the temperature changes in various environments. When irrigation was performed, we could confirm that the maximum temperature was less than 60°C. Irrigation is considered essential in endoscopic spine surgery.

LEVEL OF EVIDENCE

3.

The Arthroscopic Application of Radiofrequency in Treatment of Articular Cartilage Lesions

Articular cartilage lesion is a common disease to be treated by arthroscopic surgery. It will eventually progress to osteoarthritis without proper management, which can affect patients’ work and daily life seriously. Although mechanical debridement and laser have been used clinically for its treatment, due to their respective drawbacks, radiofrequency has drawn increasing attention from clinicians as a new technique with more advantages. However, the safety and efficacy of radiofrequency have also been questioned. In this article, the scope of application of radiofrequency was reviewed following an introduction of its development history and mechanism, and the methods to ensure the safety and effectiveness of radiofrequency through power and temperature control were summarized.

Hip Arthroscopy Versus Physical Therapy for the Treatment of Symptomatic Acetabular Labral Tears in Patients Older Than 40 Years: A Randomized Controlled Trial

BACKGROUND

Previous observational studies have suggested poor results of arthroscopic surgery for the treatment of acetabular labral tears in patients older than 40 years.

PURPOSE

To compare hip arthroscopy versus nonoperative management for symptomatic labral tears in patients older than 40 years who have limited radiographic osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

In this single-surgeon, parallel randomized controlled trial, patients older than 40 years who had symptomatic, MRI-confirmed labral tears and limited radiographic osteoarthritis (Tönnis grades 0-2) were randomized 1:1 to arthroscopic surgery with postoperative physical therapy (SPT) or physical therapy alone (PTA) using an electronic randomization program. PTA patients who achieved unsatisfactory improvement were permitted to cross over to SPT after completing ≥14 weeks of physical therapy. The primary outcomes were International Hip Outcome Tool (iHOT-33) and modified Harris Hip Score (mHHS) at 12 months after randomization, and secondary outcomes included other patient-reported outcome measures and the visual analog scale. Outcomes were assessed at baseline and at 3, 6, and 12 months after randomization. Primary analysis was performed on an intention-to-treat basis using linear mixed-effect models. Sensitivity analyses included modified as-treated analysis and treatment-failure analysis. Due to infeasibility, patients and health care providers were both unblinded.

RESULTS

The study enrolled 90 patients (46 [51.1%] SPT; 44 [48.9%] PTA); of these, 81 patients (42 [51.9%] SPT; 39 (48.1%) PTA) completed 12-month follow-up. A total of 28 of the 44 PTA patients crossed over to SPT within the study period (63.6% crossover). Intention-to-treat analysis revealed significantly greater iHOT-33 scores (+12.11; P = .007) and mHHS scores (+6.99 points; P = .04) in the SPT group than the PTA group at 12 months. Modified as-treated analysis revealed that these differences exceeded the minimal clinically important difference of 10.0 points (SPT-PTA iHOT-33, +11.95) and 8.0 points (SPT-PTA mHHS, +9.76), respectively.

CONCLUSION

In patients older than 40 years with limited osteoarthritis, arthroscopic acetabular labral repair with postoperative physical therapy led to better outcomes than physical therapy alone. Thus, age over 40 years should not be considered a contraindication to arthroscopic acetabular labral repair.

REGISTRATION

NCT03909178 (ClinicalTrials.gov identifier).

Translational relevance of the goat as a preclinical model of the human labrum and chondrolabral junction-histological study

The purpose of this study was to evaluate the histologic features of the caprine labrum, with emphasis on the chondrolabral junction, with the goal of informing the feasibility of the goat as an animal model. The left hip joint of six adolescent Spanish goats (Capra pyrenaica) was harvested and subjected to anatomical and histological assessments. Human acetabular and femoral head samples, collected during total hip arthroplasty, served as comparison samples. The caprine labrum was found to consist of mostly type I collagen with uniform crimp, with an average crimp length of 20.8 µm. Upon histological assessment, acetabular articular chondrocytes were found to express substance-P, especially near or in the chondrolabral junction. And the majority of nonvascular cells expressed α-smooth muscle actin (SMA), with no notable elastin and laminin expression. Human labrum demonstrated similar staining patterns. Overall, the goat hip was found to be homologous to the human hip, demonstrating potential as a useful animal model for future studies. This is the first report of a crimped collagen structure in the labrum. Crimped type I collagen at the chondrolabral junction imparts an extension-recovery property which allows for toleration of stress without permanent deformation, underlying the importance of its preservation during surgery. The high expression of substance-P reflects the degree to which the labrum is innervated. Finally, the expression of α-SMA with contractile characteristics could indicate the potential for chondrocyte (i.e., myochondrocytes) modeling of the extracellular matrix. Statement of Clinical Significance: Establishment of a large animal model and deeper knowledge of the histological composition of the hip joint will enhance our study of the acetabular labrum, including repair techniques. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1070-1080, 2020.

Arthroscopic Treatment of Pigmented Villonodular Synovitis of the Hip Using Puncture Capsulotomy

Pigmented villonodular synovitis (PVNS) is a monoarticular, benign tumor arising from the synovium. Although classically treated with open synovectomy, arthroscopic treatment has demonstrated good clinical outcomes. The arthroscopic management of hip PVNS has been described as technically challenging due to difficulty obtaining the appropriate exposure. The purpose of this technical report is to describe a novel technique that allows for sound excision of PVNS during hip arthroscopy using a puncture capsulotomy. Full visualization throughout the central and peripheral compartments is key to achieving meticulous surgical excision and ablation, with careful attention to the medial and lateral synovial folds and gutters. It is important to avoid chondral injury by using a high outflow rate of irrigation to maintain a constant temperature, to ablate the blood supply of nodular lesions, and to not use a shaver as this may disseminate tumor cells. Multifactorial advancements in hip arthroscopy have permitted adequate visualization and exposure of PVNS lesions, making them amenable to arthroscopic synovectomy. Puncture capsulotomy does not require capsular closure, preserves the iliofemoral ligament, and minimizes exposure of extra-articular structures to the hip joint environment. Recurrence rates are lower in arthroscopic management compared with open management, at 7.7% and 17.8%, respectively.

The influence of radio frequency ablation on intra-articular fluid temperature in the ankle joint - a cadaver study

Background

Radio frequency ablation devices have found a widespread application in arthroscopic surgery. However, recent publications report about elevated temperatures, which may cause damage to the capsular tissue and especially to chondrocytes. The purpose of this study was the investigation of the maximum temperatures that occur in the ankle joint with the use of a commercially available radio frequency ablation device.

Methods

Six formalin-fixed cadaver ankle specimens were used for this study. The radio frequency device was applied for 120 s to remove tissue. Intra-articular temperatures were logged every second for 120 s at a distance of 3, 5 and 10 mm from the tip of the radio frequency device. The irrigation fluid flow was controlled by setting the inflow pressure to 10 mmHg, 25 mmHg, 50 mmHg and 100 mmHg, respectively. The controller unit voltage setting was set to 1, 5 and 9.

Results

Maximum temperatures exceeding 50 °C/122 °F were observed for all combinations of parameters, except for those with a pressure of 100 mmHg pressure. The main critical variable is the pressure setting, which is highly significant. The controller unit voltage setting showed no effect on the temperature measurements. The highest temperature was 102.7 °C/215.6 °F measured for an irrigation flow of 10 mmHg. The shortest time span to exceed 50 °C/122 °F was 3 s.

Conclusion

In order to avoid temperatures exceeding 50 °C/122 °F in the use of radio frequency devices in arthroscopic surgeries of the ankle joint, it is recommended to use a high irrigation flow by setting the pressure difference across the ankle joint as high as feasible. Even short intervals of a low irrigation flow may lead to critical temperatures above 50 °C/122 °F.

Level of Evidence

Level II, diagnostic study.

Effects on the Distal Radioulnar Joint of Ablation of Triangular Fibrocartilage Complex Tears With Radiofrequency Energy

PURPOSE

This cadaver study investigated the temperature profile in the wrist joint and distal radioulnar joint (DRUJ) during radiofrequency energy (RFE) application for triangular fibrocartilage complex resection.

METHODS

An arthroscopic partial resection of the triangular fibrocartilage complex using monopolar and bipolar RFE was simulated in 14 cadaver limbs. The temperature was recorded simultaneously in the DRUJ and at 6 other anatomic locations of the wrist during RFE application.

RESULTS

The mean temperature in the DRUJ was 43.3 ± 8.2°C for the bipolar system in the ablation mode (60 W) and 30.4 ± 3.4°C for the monopolar system in the cut mode (20 W) after 30 seconds. The highest measured temperature in the DRUJ was 54.3°C for the bipolar system and 68.1°C for the monopolar system.

CONCLUSIONS

The application of RFE for debridement or resection of the triangular fibrocartilage complex in a clinical setting can induce peak temperatures that might cause damage to the cartilage of the DRUJ. Bipolar systems produce higher mean temperatures than monopolar devices.

CLINICAL RELEVANCE

RFE application increases the mean temperature in the DRUJ after 30 seconds to a level that may jeopardize cartilage tissue.

Outcomes for Hip Arthroscopy According to Sex and Age: A Comparative Matched-Group Analysis

BACKGROUND

Factors such as age and sex are postulated to play a role in outcomes following arthroscopy for femoroacetabular impingement; however, to our knowledge, no data currently delineate outcomes on the basis of these factors. The purpose of this study was to compare clinical outcomes of patients undergoing hip arthroscopy for femoroacetabular impingement according to sex and age.

METHODS

One hundred and fifty patients undergoing hip arthroscopy for femoroacetabular impingement by a single fellowship-trained surgeon were prospectively analyzed, with 25 patients in each of the following groups: female patients younger than 30 years of age, female patients 30 to 45 years of age, female patients older than 45 years of age, male patients younger than 30 years of age, male patients 30 to 45 years of age, and male patients older than 45 years of age. The primary outcomes included the Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL), Hip Outcome Score Sport-Specific Subscale (HOS-Sport), the modified Harris hip score (mHHS), and clinical improvement at the time of follow-up.

RESULTS

At a minimum 2-year follow-up, all groups demonstrated significant improvements in the HOS-ADL, the HOS-Sport, and the mHHS (p < 0.0001). Female patients older than 45 years of age scored significantly worse on the HOS-ADL, HOS-Sport, and mHHS compared with female patients younger than 30 years of age (p < 0.0001 for all) and female patients 30 to 45 years of age (p < 0.017 for all). Male patients older than 45 years of age scored significantly worse on all outcomes compared with male patients younger than 30 years of age (p ≤ 0.011 for all) and male patients 30 to 45 years of age (p ≤ 0.021 for all). Incorporating both sexes, patients older than 45 years of age scored significantly worse on all outcomes compared with patients younger than 30 years of age (p < 0.0001 for all) and patients 30 to 45 years of age (p ≤ 0.001 for all). Female patients older than 45 years of age had significantly reduced radiographic preoperative joint space width compared with the two other female groups and the male groups who were 45 years of age or younger (p < 0.05 for all).

CONCLUSIONS

Although all patients had significant improvements in all outcomes following hip arthroscopy, patients older than 45 years of age performed worse than younger patients, with female patients older than 45 years of age demonstrating the lowest outcome scores. In the age group of 45 years or younger, female patients performed as well as male patients in terms of hip clinical outcome scores. Overall, care must be individualized to optimize outcomes following hip arthroscopy for femoroacetabular impingement.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

What are the current indications for use of radiofrequency devices in hip arthroscopy? A systematic review

The role of radiofrequency energy (RFE) devices has been minimally studied in hip arthroscopy. The purpose of this study was to determine the role of RFE devices in hip arthroscopy through a systematic review of the literature. We searched the PubMed database using the following Medical Subject Heading terms: hip arthroscopy, hip radiofrequency, thermal capsulorrhaphy, thermal chondroplasty and radiofrequency debridement. Two authors independently reviewed the literature and included articles based on predetermined inclusion criteria. We excluded review, technique and experimental articles. After title and abstract review, we selected 293 articles for full-text review. Ten articles met the inclusion and exclusion criteria. For the included articles, a total of 305 hips underwent arthroscopy with concomitant RFE treatment at a mean age of 25.7 years. Eight articles presented patient-reported outcome (PRO) instruments, one study did not report an outcome instrument but utilized an evaluation of postoperative range of motion (ROM) and 1 year magnetic resonance image (MRI) and computed tomography (CT) imaging. The remaining article measured only the ROM pre- and postoperatively. Only one of the articles reviewed reported complications. Current evidence on the safety and indications for use of RFE devices in hip arthroscopy is insufficient. The literature shows mixed results regarding its use in hip arthroscopy. Although the use of thermal energy is not without risk, if used judiciously and appropriate precautions are taken to avoid damage to adjacent tissues, those devices can be useful for the treatment of certain intra-articular hip pathologies arthroscopically.

Arthroscopic Microfracture Technique for Cartilage Damage to the Lateral Condyle of the Tibia

This report describes the use of arthroscopic microfracture to treat a 10-year-old female patient with extensive damage to the cartilage of the lateral condyle of the tibia before epiphyseal closure, resulting in good cartilage recovery. Magnetic resonance imaging showed a defect in part of the load-bearing surface of the articular cartilage of the condyle articular of the tibia. The patient was diagnosed with damage to the lateral condyle cartilage of the tibia following meniscectomy, and arthroscopic surgery was performed. The cartilage defect measured approximately 20 × 20 mm, and microfracture was performed. Arthroscopy performed four months postoperatively showed that the cartilage defect was completely covered with fibrous cartilage, and the patient was allowed to resume sports activities. Four years postoperatively, she has had no recurrence of pain or hydrarthrosis.

Chondrolysis after hip arthroscopy

We report the case of a 58-year-old woman who presented with left hip pain and was diagnosed with femoroacetabular impingement. She underwent hip arthroscopy to repair a degenerative labral tear, as well as radiofrequency debridement and microfracture of the exposed chondral defect, and femoral osteoplasty. Two months after hip arthroscopy, hip pain and limping began. Hip radiography showed a concentric decrease of joint space and no signs of joint incongruity or osteophytosis. Revision surgery 4 months after hip arthroscopy showed that the cartilage of the femoral head was soft and separated from the subchondral bone.

Improved outcomes after hip arthroscopic surgery in patients undergoing T-capsulotomy with complete repair versus partial repair for femoroacetabular impingement: a comparative matched-pair analysis

BACKGROUND

Hip capsular management after hip arthroscopic surgery for femoroacetabular impingement (FAI) is controversial.

PURPOSE/HYPOTHESIS

To compare the clinical outcomes of patients undergoing hip arthroscopic surgery for FAI with T-capsulotomy with partial capsular repair (PR; closed vertical incision, open interportal incision) versus complete capsular repair (CR; full closure of both incisions). The hypothesis was that there would be improved clinical outcomes in patients undergoing CR compared with those undergoing PR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Consecutive patients undergoing hip arthroscopic surgery for FAI by a single fellowship-trained surgeon from January 2011 to January 2012 were prospectively collected and analyzed. Inclusion criteria included all patients between ages 16 and 65 years with physical examination and radiographic findings consistent with symptomatic FAI, with a minimum 2-year follow-up. For analysis, patients were matched according to sex and age ±2 years. Primary clinical outcomes were measured via the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sport-Specific (HOS-SS) subscales, the modified Harris Hip Score (mHHS), patient satisfaction (measured on a visual analog scale), and clinical improvement at baseline, 6 months, 1 year, and 2 years. Statistical analysis was performed utilizing Student paired and unpaired t tests, with P < .05 considered significant.

RESULTS

A total of 64 patients were included in the study, with 32 patients (12 male, 20 female) in each group. The average follow-up was 29.9 ± 2.6 months. There were no significant demographic differences between the groups. The CR group demonstrated significantly superior outcomes in the HOS-SS at 6 months (PR: 63.8 ± 31.1 vs CR: 72.2 ± 16.1; P = .039), 1 year (PR: 72.7 ± 14.7 vs CR: 82.5 ± 10.7; P = .006), and 2.5 years (PR: 83.6 ± 9.6 vs CR: 87.3 ± 8.3; P < .0001) after surgery. Patient satisfaction at final follow-up was significantly better in the CR group (PR: 8.4 ± 1.0 vs CR: 8.6 ± 1.1; P = .025). Both groups demonstrated significant improvements in the HOS-ADL (PR: 64.6 ± 17.0 to 90.7 ± 8.4 [P < .0001]; CR: 66.1 ± 15.7 to 92.1 ± 7.9 [P < .0001]) and HOS-SS (PR: 39.4 ± 23.9 to 83.6 ± 9.6 [P < .0001]; CR: 39.1 ± 24.2 to 87.3 ± 8.3 [P < .0001]) at final follow-up. There were no significant differences between the groups in the HOS-ADL at any time point. There were no significant differences in the mHHS between the groups at final follow-up (PR: 82.5 ± 5.0 vs CR: 83.0 ± 4.4; P = .364). The overall revision rate was 6.25%; all patients (n = 4) who required revision arthroscopic surgery were in the PR group (13% of 32 patients), while no patients in the CR group required revision surgery.

CONCLUSION

While significant improvements were seen at 6 months, 1 year, and 2.5 years of follow-up regardless of the closure technique, patients who underwent CR of the hip capsule demonstrated superior sport-specific outcomes compared with those undergoing PR. There was a 13% revision rate in the PR group, but no patients in the CR group required revision surgery. While longer term outcome studies are needed to determine if these results are maintained over time, these data suggest improved outcomes after CR compared with PR at 2.5 years after hip arthroscopic surgery for FAI.