Glenohumeral chondrolysis after arthroscopy: a systematic review of potential contributors and causal pathways

Debate: Intra-articular steroid injections for osteoarthritis - harmful or helpful?☆,☆☆

Intra-articular corticosteroids injections are a widely used treatment for pain from symptomatic osteoarthritis. Systematic reviews show that the treatment effect is modest compared with intra-articular saline (often considered as placebo) and lasts for 2-4 weeks on average. Potentially as a consequence of limited therapeutic duration, repeated injections are often given up to 4 injections annually. In this context of repeat injections, recent evidence has emerged that intra-articular corticosteroids might be associated with more MRI-assessed quantitative cartilage thickness loss than saline injections. Guidelines vary in the recommendation for use of intra-articular corticosteroids. Given the frequency with which intra-articular corticosteroids injections are used, the size and scale of the population with osteoarthritis, it is critical to fully understand the benefits and drawbacks of intra-articular corticosteroids injections. That is the focus of this debate article.

Fixation devices for anterior shoulder instability

PURPOSE

Over the past 40 years, advances in the development of anchors and sutures have contributed to the improvement in surgical outcomes for treatment of shoulder instability. Important choices in surgery when treating instability include the use of knotless versus knotted suture anchors, and bony versus soft tissue reconstruction techniques.

METHODS

A literature review was conducted to evaluate the history of instability of the shoulder and the results of specific fixation techniques including bony and soft tissue reconstructions as well as knotted and knotless suture anchors.

RESULTS

As knotless suture anchors have continued to grow in popularity since their development in 2001, many studies have compared this newer technique to that of the standard knotted suture anchors. In general, these studies have demonstrated no difference in patient-reported outcome measures between the two options. Additionally, the choice of bony versus soft tissue reconstructions is patient specific as it depends on the specific pathology or combination of injuries.

CONCLUSION

In each surgery performed for shoulder instability, it is vitally important that we try to restore normal anatomy. The normal anatomy is best established by knotted mattress sutures. However, loop laxity and tear through by the sutures in the capsule can eliminate this restoration, increasing risk of failure. Knotless anchors may allow better soft tissue fixation of the labrum and capsule to the glenoid, but without complete restoration of normal anatomy.

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.

Anchor Arthropathy of the Shoulder Joint After Instability Repair: Outcomes Improve With Revision Surgery

PURPOSE

To report clinical and patient-reported outcome measures (PROMs) in patients undergoing revision surgery after diagnosis of anchor-induced arthropathy.

METHODS

Patients who underwent revision arthroscopic shoulder surgery and were diagnosed with post-instability glenohumeral arthropathy performed from January 2006 to May 2018 were included in the current study. Patients were excluded if they underwent prior open shoulder procedures, if glenoid bone loss was present, or if prerevision imaging and records were incomplete or not available. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, exam findings before revision surgery, and surgical intervention. PROMs were prospectively collected before surgery and at minimum 2-year follow-up.

RESULTS

Fourteen patients were included with a mean (± standard deviation) age at presentation of 35.2 ± 12.1 years (range 16 to 59). The follow-up rate was 86%, with a mean follow-up of 3.8 years (range 1.1 to 10.6). Mean time to development of arthropathy symptoms was 48.2 months (range <1 month to 13.8 years), all presenting with pain and decreased range of motion on exam. At time of revision surgery, all patients underwent either open or arthroscopic removal of previous implants, including anchors and suture material. Six patients underwent additional revision stabilization procedures, 1 underwent total shoulder arthroplasty, and 7 underwent arthroscopic intraarticular debridement, capsular release, and chondroplasty with or without microfracture. Pain significantly improved in 79% of patients (P = .05). Significant improvements in all PROMs were observed, including 12-item Short Form (43.8 to 54.8, P < .01); Disabilities of the Arm, Shoulder, and Hand, shortened version (31.8 to 8.4, P < .01); Single Assessment Numeric Evaluation (47.0 to 84.5, P < .05); and American Shoulder and Elbow Surgeons (61.6 to 92.1, P < .01). Average external rotation significantly improved, from 31° ± 22° to 52° ± 24° (P = .02).

CONCLUSION

Rapid intervention after diagnosis, through either revision arthroscopic or open debridement and stabilization, can lead to significant improvement in range of motion, pain, and overall patient function and satisfaction.

LEVEL OF EVIDENCE

IV, retrospective case series.

Postoperative Stiffness and Pain After Arthroscopic Labral Stabilization: Consider Anchor Arthropathy

PURPOSE

To describe the key clinical, imaging, and arthroscopic characteristics of anchor arthropathy after arthroscopic shoulder stabilization procedures and, secondarily, to define risk factors for the development of anchor-induced arthropathy.

METHODS

A total of 23 patients who underwent revision arthroscopic shoulder surgery and were diagnosed with glenohumeral arthropathy were retrospectively identified from prospectively collected data registries between January 2000 and May 2018. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, and examination findings before revision surgery. Pre-revision imaging was used to assess presence of glenohumeral osteoarthritis and chondromalacia, anchors/sutures, loose bodies, and labral pathology. The same parameters were recorded intraoperatively during revision surgery. Descriptive statistics were performed for demographic data and means with standard deviations were calculated for continuous data. A McNemar-Bowker test was used to analyze marginal homogeneity between preoperative imaging and intraoperative findings.

RESULTS

Mean age at presentation was 33.4 ± 11.7 years (range 16-59, 17 male patients; 6 female patients). More than one half (13/23) developed symptoms within 10 months after index arthroscopic procedure (mean 32.2 ± 59.9 months, range <1 to 165.2 months) with 87% presenting with pain and 100% presenting with loss of motion on examination. Plain radiographs demonstrated humeral osteoarthritis in 57% (13/23) of patients, magnetic resonance imaging (MRI) revealed recurrent labral pathology in 19 of 23 (83%) patients, potential proud implants in 12 of 23 (52%), and loose bodies in 12 of 23 (52%). Intraoperatively, all had evidence of osteoarthritis; 22 of 23 (96%) had prominent implants. Humeral head chondromalacia was present in 21 of 23 patients (91%), the majority of which was linear stripe wear, and 6 of 23 (26%) had severe global glenohumeral osteoarthritis. Statistical analysis revealed a 54.5% (95% confidence interval 0.327-0.749) sensitivity of MRI identification of proud implants with a specificity of 100% (95% confidence interval 0.055-1). The ability of MRI to accurately assess chondromalacia of the humeral head (P = .342) or glenoid (P = .685) was not statistically significant.

CONCLUSIONS

Anchor arthropathy is characterized by symptoms of pain and stiffness on examination and in many cases develops early after stabilization surgery (<10 months). Implants were implicated in the majority of cases of humeral head chondromalacia. MRI scans may produce false-negative identification of proud implants and can be a poor predictor of the severity of chondromalacia and intra-articular pathology; thus, a high index of clinical suspicion is necessary in patients with motion loss and pain postoperatively.

LEVEL OF EVIDENCE

Level IV, case series.

Relationship Between Age at Initial Shoulder Instability and Overall Outcomes After Arthroscopic Bankart Repair: Mean 6-Year Follow-up

Background:

Age at surgery plays a crucial role in the frequency of recurrent shoulder instability. However, there are few studies that evaluate the relationship between age at initial shoulder instability and overall outcomes after stabilization surgery.

Purpose:

To compare clinical outcomes and structural changes after arthroscopic Bankart repair in patients who experienced initial shoulder instability during adolescence versus those with later onset instability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This study included patients who underwent arthroscopic Bankart repair at a single institution between 2007 and 2017. Comparisons were made between patients who experienced initial shoulder instability during adolescence (age 13-19 years; group A) and those with later onset instability (age 20-35 years; group B). Clinical outcomes (recurrence rate, postoperative pain, functional scores, active range of motion, and return to sports) and structural changes demonstrated by magnetic resonance imaging (MRI) were evaluated at minimum 2-year follow-up. In addition, functional outcomes within each group were compared between the patients with and without postoperative recurrence.

Results:

A total of 58 patients were included (24 patients in group A and 34 patients in group B). The mean follow-up was 72.1 months. Group A demonstrated a significantly higher recurrence rate than group B (41.7% vs 11.8%, respectively; P = .009; risk ratio, 5.36 [95% CI, 1.43-20.09]) as well as significantly lower Rowe (76.9 ± 20.1 vs 88.7 ± 13.2, respectively; P = .01) and Constant-Murley scores (92.2 ± 7.6 vs 96.3 ± 4.2, respectively; P = .01). Postoperative MRI revealed no significant structural differences between the groups regarding the glenoid labrum, glenohumeral cartilage, or osseous reaction around the implanted anchors. In group A, patients with recurrence had less satisfaction regarding postoperative sports level than those without recurrence, whereas in group B, patients with recurrence had more postoperative pain and functional impairment compared with those without recurrence.

Conclusion:

Initial shoulder instability during adolescence was associated with a higher recurrence rate and lower functional scores after arthroscopic Bankart repair compared with later onset instability, although no significant structural differences were found between the groups on MRI at a mean 6-year follow-up.

Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?

Osteoarthritis (OA) of the hip and knee is among the most common joint disorders. Intra-articular corticosteroid (IACS) injections are frequently performed to treat OA and other joint-related pain syndromes; however, there is conflicting evidence on their potential benefit. There is a lack of prospective and large retrospective studies evaluating potential joint findings, including increased risk for accelerated OA progression or adverse joint events, after treatment with IACS injection. Four main adverse joint findings have been structurally observed in patients after IACS injections: accelerated OA progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction, including bone loss. Physicians, including radiologists, should be familiar with imaging findings and patient characteristics that may help them identify potential joints at risk for such events. The purpose of this report is to review the existing literature, describe observed adverse joint events after IACS injections, and provide an outlook on how this may affect clinical practice. Additional research endeavors are urgently needed to better understand and identify risk factors prior to intervention and to detect adverse joint events after injection as early as possible to prevent or minimize complications.

Suture wear particles cause a significant inflammatory response in a murine synovial airpouch model

Background

Commonly used contemporary orthopaedic sutures have been identified as a potential causative factor in the development of post-arthroscopic glenohumeral chondrolysis. Currently, little is known about the body’s immune response to these materials. The aim of this study was to examine the biological response of synovial tissue to three commonly used orthopaedic sutures, using a murine airpouch model.

Methods

Fifty rats were used in this study (ten per group). An airpouch was created in each rat, and test materials were implanted. Test materials consisted of an intact polyethylene terephthalate suture with a polybutilate coating (suture A), an intact polyethylene suture braided around a central polydiaxannone core (suture B), an intact polyethylene/polyester cobraid suture with a silicone coating (suture C), and particles of suture C (particles C). Rats were sacrificed at 1 or 4 weeks following implantation. Histological (multinucleated giant cell count) and immunohistochemical (expression of matrix metalloproteinases MMP-1,-2,-3,-9,-13) markers of inflammation were examined.

Results

Multinucleated giant cells were present in all specimens containing suture material but not in the control specimens. No significant differences were found in the number of giant cells between the intact suture groups at either time point. Significantly higher numbers of giant cells were noted in the particles C group compared to the intact suture C group at both time points (p = 0.021 at 1 week, p = 0.003 at 4 weeks). Quantitative analysis of immunohistochemical staining expression at 4 weeks showed that significantly more MMP (-1,-2,-9,-13) was expressed in the particles C group than the intact suture C group (p = 0.024, p = 0.009, p = 0.002, and p = 0.007 for MMP-1, MMP-2, MMP-9, and MMP-13, respectively). No significant difference was seen in the expression of MMP-3 (p = 0.058).

Conclusions

There were no differences observed between the biological reactivity of commonly used intact orthopaedic sutures A, B, and C. However, wear particles of suture C elicited a significantly greater inflammatory response than intact suture alone. This was confirmed by increased numbers of multinucleated giant cells as well as MMP ( -1,-2,-9,-13) expression. Further studies are needed to determine whether this inflammatory response may play a role in the development of post-arthroscopic glenohumeral chondrolysis or interfere with biological healing. These findings have important clinical implications relating to surgical technique and surgical implant design.

Protective effects of platelet-rich plasma against lidocaine cytotoxicity on canine articular chondrocytes

Background

Lidocaine (LD) is one of the most commonly used local anesthetics for performing arthroscopic surgery and managing of osteoarthritic pain in both human and veterinary medicine. However, over the last years, several studies have focused on the chondrotoxic effects of LD. In order to ensure that intra-articular lidocaine is safe to use, treatments aimed at mitigating chondrocyte death have recently been investigated. The aim of this study is to evaluate the possible protective effects of platelet-rich plasma (PRP) against LD cytotoxicity on canine articular chondrocytes.

Results

Articular canine chondrocytes, were exposed to 1% or 1.8% LD alone or in co-presence with 10% PRP for 30 min. In order to evaluate the effects of PRP pre-treatments, experiments were carried out on cells cultured in serum-free medium-or in medium supplemented with 10% PRP or 10% fetal bovine serum. Cell viability was evaluated by methyl thiazolyl tetrazolium assay and cell apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/propidium iodide. The results showed that LD significantly reduced canine chondrocytes viability, probably due to apoptosis induction. Pre-treatment or the co-presence of PRP in the media restored the number of viable chondrocytes. The PRP also seemed to protect the cells from LD-induced apoptosis.

Conclusions

Pre-treatments and/or the simultaneous administration of PRP reduced LD-induced cytotoxicity in canine chondrocytes. Further in vivo studies are required to determine whether PRP can be used as a save protective treatment for dogs receiving intra-articular LD injections.

Rapid Progressive Osteonecrosis of the Humeral Head After Arthroscopic Rotator Cuff Surgery

PURPOSE

To verify the clinical features and the risk factors of rapid progressive osteonecrosis of the humeral head after arthroscopic rotator cuff surgery (ARCS).

METHODS

Data and medical records of 24 patients who had rapid progressive collapse of the humeral head after ARCS performed from October 2012 to March 2016 were retrospectively analyzed. Among them, 8 patients demonstrated no evidence of osteonecrosis of the humeral head preoperatively yet developed rapid progressive collapse of the humeral head within 12 months after ARCS.

RESULTS

All patients were women with a mean age of 64.0 years (range, 52-74 years), and all of them had surgery on their dominant side. Sudden pain developed at a mean 4 months (range, 0-6 months) after index surgery. The rapid progressive collapse of the humeral head occurred within 12 months after index surgery. No clear risk factor or evidence supporting an association between ARCS and humeral head osteonecrosis was found.

CONCLUSIONS

Although the cause of the rapid progressive humeral head osteonecrosis after ARCS still needs to be established, surgeons should be aware of the possible development of humeral head osteonecrosis after ARCS, especially in older women with dominant arm involvement.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Local Infiltration Analgesia Compared With Epidural and Intravenous PCA After Surgical Hip Dislocation for the Treatment of Femoroacetabular Impingement in Adolescents

BACKGROUND

Open treatment of femoroacetabular impingement (FAI) through a surgical hip dislocation (SHD) approach has been reported to allow for improvement in pain and function. However, the approach require a trochanteric osteotomy and may be associated with high level of pain after surgery. Currently, there is no systematic approach for pain management after SHD for treatment of FAI.

METHODS

A retrospective chart review was used to collect data from 121 subjects (12 to 21 y and below) who received periarticular local infiltration analgesia (LIA, n=20), epidural analgesia (n=72), or intravenous patient-controlled analgesia (PCA, n=29) after SHD from January 2003 to June 2014. Verbal pain scores, opioid consumption, incidence of side effects/complications, and length of hospital stay (LOS) were recorded. All nonopioid medications with analgesic potential were included in the statistical models as potential confounding variables RESULTS:: Twelve hours after surgery, the odds of moderate/severe pain were higher in the PCA group (odds ratio, 20.5; 95% confidence interval (CI), 1.7-243.8; P=0.0166] and epidural group (odds ratio, 5.2; 95% CI, 0.7-92.0; P=0.3218) compared with the LIA group. There was no difference in pain scores across all groups 1 hour (P=0.0675) or 24 hours (P=0.3473) postoperatively. Total opioid consumption in the LIA group was 59.8% (95% CI, 15.0%-81.0%; P=0.0175) lower than the total opioid consumption in the epidural group and 60.7% (95% CI, 17.3-81.3; P=0.0144) lower than the total opioid consumption in the PCA group. LOS was increased in the epidural (mean difference, 22.1; 95% CI, 6.8-37.4 h; P=0.0051) and PCA (mean difference, 16 h; 95% CI, 1-31.5 h; P=0.0367) groups relative to the LIA group. There was 0 (0%) complication in the LIA group compared with 11 (15.3%) in the epidural group.

CONCLUSIONS

LIA was more effective at controlling pain 12 hours after surgery in comparison with PCA with similar pain control to epidural. LIA was associated with significantly lower need for opioids and shorter LOS compared with the PCA and epidural protocols. Periarticular infiltration should be considered for pain management after SHD for treatment of FAI in adolescents.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Pain Management After Outpatient Shoulder Arthroscopy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Effective postoperative pain management after shoulder arthroscopy is a critical component to recovery, rehabilitation, and patient satisfaction.

PURPOSE

This systematic review provides a comprehensive overview of level 1 and level 2 evidence regarding postoperative pain management for outpatient arthroscopic shoulder surgery.

STUDY DESIGN

Systematic review.

METHODS

We performed a systematic review of the various modalities reported in the literature for postoperative pain control after outpatient shoulder arthroscopy and analyzed their outcomes. Analgesic regimens reviewed include regional nerve blocks/infusions, subacromial/intra-articular injections or infusions, cryotherapy, and oral medications. Only randomized control trials with level 1 or level 2 evidence that compared 2 or more pain management modalities or placebo were included. We excluded studies without objective measures to quantify postoperative pain within the first postoperative month, subjective pain scale measurements, or narcotic consumption as outcome measures.

RESULTS

A combined total of 40 randomized control trials met our inclusion criteria. Of the 40 included studies, 15 examined nerve blocks, 4 studied oral medication regimens, 12 studied subacromial infusion, 8 compared multiple modalities, and 1 evaluated cryotherapy. Interscalene nerve blocks (ISBs) were found to be the most effective method to control postoperative pain after shoulder arthroscopy. Increasing concentrations, continuous infusions, and patient-controlled methods can be effective for more aggressively controlling pain. Dexamethasone, clonidine, intrabursal oxycodone, and magnesium have all been shown to successfully improve the duration and adequacy of ISBs when used as adjuvants. Oral pregabalin and etoricoxib administered preoperatively have evidence supporting decreased postoperative pain and increased patient satisfaction.

CONCLUSION

On the basis of the evidence in this review, we recommend the use of ISBs as the most effective analgesic for outpatient arthroscopic shoulder surgery.

Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes

BACKGROUND

Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns.

OBJECTIVES

The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes.

METHODS

The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500 μM was determined by LIVE/DEAD assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species.

RESULTS

On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaine<bupivacaine<lidocaine. Vitamin C effectively improved the reduced chondrocyte viability and decreased the raised apoptosis levels following exposure to anesthesia. At higher doses, vitamin C was found efficient in reducing the generation of reactive oxygen species and as well down-regulate the expressions of caspases 3 and 9.

CONCLUSIONS

Vitamin C was observed to effectively protect chondrocytes against the toxic insult of local anesthetics ropivacaine, bupivacaine and lidocaine.

Performance Comparison of a Pretied Suture Knot With Three Conventional Arthroscopic Knots

PURPOSE

To compare the knot characteristics of a pretied suture knot with 3 of the most commonly used arthroscopic knots tied with various high-strength sutures.

METHODS

Three commonly used arthroscopic knots (surgeon's knot, Seoul Medical Center, and Duncan loop) tied with no. 2 high-strength sutures were compared with a pretied knot secured with either 1, 2, or 3 reversed half hitches (RHAPS). An orthopaedic sports medicine surgeon and fellow tied a total of 120 knots. All knot combinations were tested for strength, knot bulk, cyclic loop elongation, ultimate loop elongation, and ultimate strength.

RESULTS

All pretied configurations had statistically significant improved strength (P = .048, P ≤ .001, and P < .001) versus all other knot groups with mean ± standard deviation loads of 206.3 ± 37.5, 285.6 ± 68.6, and 357.6 ± 61.1 N, respectively. The pretied knot with 1, 2, or 3 RHAPs has significantly smaller volume than the arthroscopic knots in all suture materials. All pretied knot configurations demonstrated no significant difference in cyclic loop elongation compared with standard arthroscopic knots; however, they had a statistically significant lower ultimate loop elongation (P = .001 for each pretied knot configuration).

CONCLUSIONS

Compared with other commonly tied arthroscopic knots using no. 2 high-strength suture, the pretied knot with doubled no. 1 high-tensile-strength suture tied with 1, 2, or 3 RHAPs results in a statistically significantly improved strength. The pretied knot has an equivalent cyclic loop elongation and lower ultimate loop elongation with all RHAP configurations. The pretied knot with 2 or 3 RHAPs has a significantly higher ultimate strength than all combinations of arthroscopic knots excluding one. The pretied knot with 1, 2, or 3 RHAPs has significantly less knot volume than all other knots tested and offers a more reproducible knot.

CLINICAL RELEVANCE

The pre-tied knot offers equivalent or improved strength while having a smaller knot volume.

Management of complications after rotator cuff surgery

Rotator cuff repair (RCR) is a common procedure performed by orthopedic surgeons via arthroscopic, open, or mini-open techniques. While this surgery is considered to be of low morbidity, several potential complications can arise either intraoperatively or during the postoperative time period. Some of these complications are related to the surgical approach (arthroscopic or open), while others are patient dependent. Many of these complications can be managed through nonoperative means; however, early recognition and timely treatment is essential in limiting the long-term sequela and improving patient outcome. There are several different ways to classify complications after RCR repair: timing, severity, preventability, whether or not the pathology is intra- or extra-articular, and the type of treatment necessary. It is essential that the surgeon is cognizant of the etiology contributing to the failed RCR surgery in order to provide timely and proper management.

Effect of intra-articular local anesthesia on articular cartilage in the knee

PURPOSE

To evaluate the hypothetical toxic effect of local anesthetics on the articular cartilage using patient data from autologous chondrocyte cultivation with different anesthesia types used for arthroscopic cartilage biopsy specimen procurement.

METHODS

A retrospective analysis of patient data from the national autologous chondrocyte implantation registry and the corresponding hospital records was approved by the National Medical Ethics Committee. Articular cartilage biopsy specimens from the knees of 49 consecutive patients assigned for autologous chondrocyte implantation (aged 14 to 44 years) were procured from the non-weight-bearing articular surface during arthroscopy under general anesthesia (12 patients), spinal anesthesia (18 patients), or local anesthesia (intra-articular injection of 15 to 20 mL of 2% lidocaine hydrochloride) (19 patients). All the biopsy specimens were further manipulated following the same chondrocyte cultivation protocol. General patient data and surgery-related parameters, together with chondrocyte viability, population doublings, and chondrocyte morphology in biopsy specimens and primary cell cultures, were analyzed and compared across different types of anesthesia.

RESULTS

Patients in the general, spinal, and local anesthesia groups showed no statistical differences in age (27 years, 29 years, and 32 years, respectively), duration of surgery (36 minutes, 37 minutes, and 39 minutes, respectively), weight of biopsy specimens (110 mg, 178 mg, and 130 mg, respectively), cell viability in cartilage biopsy specimens (67%, 69%, and 78%, respectively) or primary cultures (95%, 95%, and 95%, respectively), and population doublings (5.2, 5.2, and 5.2, respectively). Similar chondrocyte morphology in primary cell cultures was observed among the 3 groups.

CONCLUSIONS

This retrospective study showed that a single intra-articular injection of lidocaine hydrochloride used for knee arthroscopy did not influence the viability, morphology, and cultivation potential of chondrocytes in articular cartilage biopsy specimens assigned for autologous chondrocyte implantation.

LEVEL OF EVIDENCE

Level IV, retrospective comparative study.

Inhibition of chondrocyte and synovial cell death after exposure to commonly used anesthetics: chondrocyte apoptosis after anesthetics

BACKGROUND

An intra-articular injection of local anesthetics is a common procedure for diagnostic and therapeutic purposes. It has been shown that these agents are toxic to articular cartilage and synovial tissue in a dose- and time-dependent fashion, and in some cases, they may lead to postarthroscopic glenohumeral chondrolysis (PAGCL). However, the role of apoptosis in cell death is still unclear, and the potential role of apoptosis inhibition in minimizing chondrocyte and synovial cell death has not been reported.

PURPOSE

(1) To quantify the degree of apoptotic cell death in chondrocytes and synovial cells exposed to local anesthetics, and (2) to determine whether caspase inhibition could reduce cell death.

STUDY DESIGN

Controlled laboratory study.

METHODS

Human chondrocytes and synovial cells were expanded in vitro and exposed to normal saline, 0.5% bupivacaine, 0.5% ropivacaine, 1% lidocaine, or 1:1000 epinephrine for 90 minutes. Apoptosis was then detected at 1, 3, 5, and 7 days after exposure using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) and immunohistochemistry. Apoptosis was then inhibited using the pan-caspase inhibitor z-vad-fmk. Results were normalized to normal saline controls and analyzed by generalized regression models and pairwise confidence intervals.

RESULTS

Analysis of cumulative chondrocyte apoptosis relative to controls after anesthetic exposure demonstrated more than 60% cell death with 0.5% bupivacaine and 1:1000 epinephrine. The greatest chondroprotective effect of caspase inhibition occurred with 0.5% ropivacaine. Similarly, in synovial cells, epinephrine was also very cytotoxic; however, 1% lidocaine induced the most apoptosis. Synovial cells exposed to 0.5% ropivacaine were again most sensitive to protective caspase inhibition.

CONCLUSION

Local anesthetics induce chondrocyte and synovial cell apoptosis in a time-dependent fashion, with peak apoptosis occurring 5 days after exposure. Both chondrocytes and synovial cells are most sensitive to caspase inhibition after exposure to 0.5% ropivacaine.

CLINICAL RELEVANCE

Apoptosis inhibition may be an effective strategy in minimizing chondrocyte and synovial cell death after exposure to anesthetics. Further investigation is clinically warranted.

In vitro temperature evaluation during cement augmentation of proximal humerus plate screw tips

BACKGROUND

The treatment of proximal humerus fractures in patients with poor bone quality remains a challenge in trauma surgery. Augmentation with polymethylmethacrylate (PMMA) cement is a possible method to strengthen the implant anchorage in osteoporotic bone and to avoid loss of reduction and reduce the cut-out risk. The polymerisation of PMMA during cement setting leads, however, to an exothermic reaction and the development of supraphysiological temperatures may harm the bone and cartilage. This study addresses the issue of heat development during augmentation of subchondrally placed proximal humerus plate screws with PMMA and the possible risk of bone and cartilage necrosis and apoptosis.

METHODS

Seven fresh frozen humeri from geriatric female donors were instrumented with the proximal humerus interlocking system (PHILOS) plate and placed in a 37°C water bath. Thereafter, four proximal perforated screws were augmented with 0.5 ml PMMA each. During augmentation, the temperatures in the subchondral bone and on the articular surface were recorded with K-type thermocouples. The measured temperatures were compared to threshold values for necrosis and apoptosis of bone and cartilage reported in the literature.

RESULTS

The heat development was highest around the augmented tips of the perforated screws and diminished with growing distance from the cement cloud. The highest temperature recorded in the subchondral bone reached 43.5°C and the longest exposure time above 42°C was 86s. The highest temperature measured on the articular surface amounted to 38.6°C and the longest exposure time above 38°C was 5 min and 32s.

CONCLUSION

The study shows that augmentation of the proximal screws of the PHILOS plate with PMMA leads to a locally limited development of supraphysiological temperatures in the cement cloud and closely around it. The critical threshold values for necrosis and apoptosis of cartilage and subchondral bone reported in the literature, however, are not reached. In order to avoid cement extravasation, special care should be taken in detecting perforations or intra-articular cracks in the humeral head.

Arthroscopic surgical tools: a source of metal particles and possible joint damage

PURPOSE

Our goals were (1) to characterize metal microparticles created by standard arthroscopic instruments and (2) to examine the in vitro cellular responses induced by those particles, including possible synergistic effects with local anesthetic.

METHODS

We applied standard surgical tools to 16 foam bone blocks immersed in saline solution (plus 3 non-instrumented controls). Eight specimens underwent 4 minutes of exposure to a 4.0-mm full-radius shaver rotating forward at 6,000 rpm. In the other blocks, 4 holes were created with a 3.0-mm drill through a sleeve. Particles were isolated onto silicon wafers by density gradient ultra-centrifugation, and scanning electron microscopy was used to analyze a minimum of 1,000 particles per wafer. Metal particles were then isolated and purified. Aliquots of sterilized micro-particles were applied to cultured bovine chondrocytes (with or without local anesthetic) and to cultured human or bovine synoviocytes. Chondrocyte viability was assessed with live/dead cell assay by flow cytometry. Synoviocyte responses were assessed with quantitative polymerase chain reaction.

RESULTS

Stainless steel or aluminum particles were found in each sample (the same composition as surgical instruments). The mean particle size was 1 to 2 μm (range, 50 nm to 20 μm). Chondrocyte exposure (1 hour) to metal debris induced a small but statistically significant increase in cell death, without any synergistic effect of local anesthetic. Proinflammatory chemokines were consistently upregulated in both human and bovine synoviocytes exposed to metallic microparticles for 3, 24, and 48 hours.

CONCLUSIONS

This study shows that metallic microdebris is liberated by common arthroscopic instruments, at scales much smaller than previously recognized. These particles are bioactive, as shown by the in vitro synoviocyte responses initiated by metallic microparticles.

CLINICAL RELEVANCE

Our findings suggest that metallic microparticles could induce intra-articular damage through a synoviocyte-mediated cytokine response if their concentrations reach clinically significant levels.

Postoperative fentanyl patch versus subacromial bupivacaine infusion in arthroscopic shoulder surgery

PURPOSE

The purpose of our study was to compare the effectiveness of subacromial bupivacaine infusion and a transdermal fentanyl patch in the treatment of postoperative pain after arthroscopic shoulder surgery.

METHODS

Sixty patients with rotator cuff disease scheduled for elective arthroscopic shoulder surgery were enrolled in the study. For the treatment of postoperative pain, 30 patients constituted group F and received a 12.0-μg/h fentanyl patch for 72 hours and saline solution infusion in a subacromial manner at the rate of 4 mL/h. The remaining 30 patients constituted group B and received a placebo patch and an infusion of 2.5-mg/mL bupivacaine in a subacromial manner for 72 hours. The primary outcome measure was the postoperative numerical rating scale pain score. The consumption of opioids, ibuprofen, and acetaminophen was also recorded. The Constant scores and general recovery were followed up until the 90th postoperative day.

RESULTS

There was no statistically significant difference in the numerical rating scale scores (P = .60) between the groups. No differences in the use of rescue analgesic were observed except that the patients receiving bupivacaine used more ibuprofen (median, 1,200 mg v 600 mg) during the day of surgery (P = .042). No difference was found in general recovery between the groups.

CONCLUSIONS

A fentanyl patch delivering 12-μg/h fentanyl offers an easy and safe treatment option as a part of multimodal analgesia with few adverse effects in the treatment of postoperative pain in a carefully selected patient group after arthroscopic shoulder surgery.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

The effect of local anaesthetics on synoviocytes: a possible indirect mechanism of chondrolysis

PURPOSE

While the effect of local anaesthetics on chondrocyte viability is widely documented, the effect of these medications on synoviocytes is largely unknown. The purpose of this study was to understand the effect of 0.5 % bupivacaine and 0.5 % bupivacaine with epinephrine on synoviocyte viability, cytokine and growth factor release, and breakdown product formation.

METHODS

Rabbit fibroblast-like synoviocyte (Type B) cultures were perfused with 0.5 % bupivacaine or 0.5 % bupivacaine with epinephrine (1:200,000) for 24 h. Cell viability was evaluated using a two-colour fluorescence assay. The supernatant was analysed using multiplex inflammatory and matrix metalloproteinase assays.

RESULTS

Synoviocytes treated for 24 h with 0.5 % bupivacaine with epinephrine demonstrated a significant decrease in viability (31.3 ± 19.4 % cell death) when compared with synoviocytes cultured in control media (3.8 ± 1.3 % cell death, p = 0.000) and those cultured in 0.5 % bupivacaine alone (12.6 ± 11.1 % cell death, p = 0.003). No significant decrease in cell viability was observed in synoviocytes treated with 0.5 % bupivacaine compared to those in control media (12.6 ± 11.1 % vs 3.8 ± 1.3 % cell death, p = 0.194). Significantly greater amounts of MMP-1 (47.0 ± 9.2 pg/ml) and MMP-3 (250.0 ± 68.8 pg/ml) were observed in 0.5 % bupivacaine cultures compared with controls (14.3 ± 14.3, p = 0.023 and 72.0 ± 84.9, p = 0.045, respectively).

CONCLUSIONS

0.5 % bupivacaine with epinephrine caused a significant increase in cell death of the synoviocytes, while 0.5 % bupivacaine alone produced cell injury and a significant release of matrix metalloproteinases, which may also lead to indirect injury of the surrounding chondrocytes. These results may help explain the onset of chondrolysis observed in patients who have been treated with intra-articular local anaesthetics.

Postarthroscopic humeral head osteonecrosis treated with reverse total shoulder arthroplasty

Although postarthroscopic glenohumeral chondrolysis has become a well-known disastrous complication of arthroscopic shoulder surgery, little is known about postarthroscopic humeral head osteonecrosis. This article describes 3 patients who were referred to the authors' practice with end-stage osteonecrosis after an arthroscopic rotator cuff repair or debridement.Three patients (average age, 63.3 years) presented to the authors' practice reporting severe shoulder pain after a rotator cuff debridement or repair was performed at an outside facility. After an interval period of mild improvement, all patients experienced progressive pain and loss of shoulder range of motion at a mean of 4.8 months postoperatively. Plain radiographs and magnetic resonance imaging obtained prior to the index operation showed no evidence of osteonecrosis. Postoperatively, progressive clinical and radiographic evidence showed humeral head osteonecrosis and subsequent glenohumeral destruction with cuff tear arthropathy. The authors managed all patients with a reverse total shoulder arthroplasty due to severe glenohumeral arthrosis and massive rotator cuff tears not amendable to repair. Satisfactory results were achieved in all cases.Although many complications of arthroscopic shoulder surgery are documented, little is known about postarthroscopic humeral head osteonecrosis. Shoulder surgeons should be aware of this potential complication when performing arthroscopic rotator cuff surgery and when evaluating painful and stiff postarthroscopic shoulders.

Dislocation arthropathy and drill hole appearance in a mid- to long-term follow-up study after arthroscopic Bankart repair

PURPOSE

The aim of this study was to perform a prospective mid- to long-term clinical and radiographic follow-up after arthroscopic Bankart repair using absorbable tacks with special emphasis on the development of dislocation arthropathy.

METHODS

Thirty-four shoulders in 32 patients with post-traumatic shoulder instability were included in the study. Clinical and radiographic follow-ups took place after approximately 2 and 8 years.

RESULTS

Thirty-four of 34 (100 %) shoulders in 32 patients returned for the follow-up examination after 95 (53-129) months. Pre-operatively, none of the shoulders had any arthropathy changes. At follow-up, 8/34 (24 %) had minor changes, 6/34 (18 %) had moderate changes, and none had severe arthropathy changes, a significant increment compared with the pre-operative figures (p = 0.005). At follow-up, the drill holes in 24 % of the shoulders still had not healed radiographically. The failure rate in terms of stability was 3/34 (9 %) re-dislocations and 3/34 (9 %) subluxations.

CONCLUSION

Eight years after arthroscopic Bankart repair using absorbable tacks, 41 % of the shoulders displayed some degree of radiographic arthropathy changes and in 24 % the drill holes had not yet radiographically healed. There was no correlation between clinical outcome or drill hole appearance and the development of arthropathy changes.

LEVEL OF EVIDENCE

III.

Thermal stress potentiates bupivacaine chondrotoxicity

PURPOSE

The primary objective of this study was to determine whether thermal stress potentiates the chondrotoxic effect of bupivacaine, resulting in decreased articular chondrocyte viability compared with exposure to bupivacaine alone.

METHODS

Bovine articular cartilage explants and cultured chondrocytes were treated with a range of thermal exposures (10 to 20 minutes at 37°C to 65°C) to create time/temperature viability curves and to determine threshold conditions for cell death. A second set of experiments was performed to determine whether subthreshold thermal stress potentiates bupivacaine toxicity. Explants were exposed to 37°C or 55°C for 10 or 20 minutes, and cultured chondrocytes were exposed to 37°C or 45°C for 10 or 20 minutes. Thirty minutes later, the explants and chondrocytes were treated with either 0.9% normal saline solution or 0.5% bupivacaine for 30 minutes. Chondrocyte viability was quantified 24 hours after treatment.

RESULTS

There was a temperature- and time-dependent decrease in chondrocyte viability above the thermo-toxicity threshold in both intact cartilage explants and cultured chondrocytes (55°C and 45°C, respectively; P < .05). Chondrocyte viability in cartilage explants was significantly lower after treatment with thermal stress for 10 or 20 minutes followed by bupivacaine for 30 minutes compared with treatment with bupivacaine at 37°C (bupivacaine and 55°C for 10 minutes, 0.09% ± 0%; bupivacaine and 55°C for 20 minutes, 0.08% ± 0%; bupivacaine and 37°C for 10 minutes, 37.4% ± 1.2% [P < .001]; and bupivacaine and 37°C for 20 minutes, 47.1% ± 0.8% [P < .001]). A similar trend was seen in cultured chondrocytes, although it was not statistically significant (P > .05).

CONCLUSIONS

Thermal stress potentiates the chondrotoxic effects of bupivacaine in intact cartilage, leading to decreased chondrocyte viability compared with exposure to bupivacaine alone.

CLINICAL RELEVANCE

Intra-articular injection of bupivacaine after arthroscopic procedures during which cartilage is exposed to elevated temperatures, such as with prolonged use of radiofrequency probes, may increase the risk of chondrocyte toxicity.

Hyaluronan protects bovine articular chondrocytes against cell death induced by bupivacaine at supraphysiologic temperatures

BACKGROUND

Bupivacaine and supraphysiologic temperature can independently reduce cell viability of articular chondrocytes. In combination, these 2 deleterious factors could further impair cell viability.

HYPOTHESIS

Hyaluronan may protect chondrocytes from death induced by bupivacaine at supraphysiologic temperatures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bovine articular chondrocytes were treated with hyaluronan at physiologic (37°C) and supraphysiologic temperatures (45°C and 50°C) for 1 hour and then exposed to bupivacaine for 1 hour at room temperature. Cell viability was assessed at 3 time points: immediately after treatment, 6 hours later, and 24 hours later using flow cytometry and fluorescence microscopy. The effects of hyaluronan on the levels of sulfated glycosaminoglycan in the chondrocytes were determined using Alcian blue staining.

RESULTS

(1) Bupivacaine alone did not induce noticeable chondrocyte death at 37°C; (2) bupivacaine and temperature synergistically increased chondrocyte death, that is, when the chondrocytes were conditioned to 45°C and 50°C, 0.25% and 0.5% bupivacaine increased the cell death rate by 131% to 383% in comparison with the phosphate-buffered saline control group; and (3) addition of hyaluronan reduced chondrocyte death rates to approximately 14% and 25% at 45°C and 50°C, respectively. Hyaluronan's protective effects were still observed at 6 and 24 hours after bupivacaine treatment at 45°C. However, at 50°C, hyaluronan delayed but did not prevent the cell death caused by bupivacaine. One-hour treatment with hyaluronan significantly increased sulfated glycosaminoglycan levels in the chondrocytes.

CONCLUSION

Bupivacaine and supraphysiologic temperature synergistically increase chondrocyte death, and hyaluronan may protect articular chondrocytes from death caused by bupivacaine.

CLINICAL RELEVANCE

This study provides a rationale to perform preclinical and clinical studies to evaluate whether intra-articular injection of a mixture of bupivacaine and hyaluronan after arthroscopic surgery may protect against bupivacaine's chondrotoxicity.

Joint chondrolysis

Although the disease was first described in the hip, reports of chondrolysis in nearly all diarthrodial joints have since emerged with considerable variations in the literature.Despite speculation among clinicians and researchers about the implicit causal pathways and etiologic contributors associated with chondrolysis, definitive answers remain elusive.The term chondrolysis has been applied to varied levels of joint cartilage destruction from focal chondral defects to diffuse cartilage loss, revealing a lack of consistency in the application of diagnostic criteria to guide differential disease classification.Differentiating between the various potential etiologies associated with chondrolysis provides opportunities for the prevention of the disease.

Effects of local anesthetics on articular cartilage

BACKGROUND

Recent basic science studies have demonstrated local anesthetic chondrotoxicity in vivo and in vitro in both human and animal cartilage. Clinically, chondrolysis associated with the use of intra-articular local anesthetic pain pumps has been described by several groups. This has raised concern regarding the clinical use of intra-articular local anesthetics.

METHODS

The authors undertook a review of the current orthopaedic literature on local anesthetic chondrotoxicity and its potential relationship to clinical chondrolysis.

RESULTS

Local anesthetics such as bupivacaine, lidocaine, and ropivacaine are chondotroxic to human articular cartilage in vitro, although ropivacaine is less so. The evidence suggests that there is a greater risk for chondrolysis with a longer exposure to a higher concentration of local anesthetic, such as with a pain pump, than with a single injection. However, late cellular and metabolic changes are seen after even a single injection of bupivacaine in animal models, and the loss of an intact cartilage matrix also leads to more extensive chondrocyte death. Some studies suggest that additives and the pH of the local anesthetic solution may also play a role in chondrotoxicity.

CONCLUSION

Intra-articular local anesthetics should be used with caution, especially continuous infusions of bupivacaine and lidocaine at high concentrations in joints with compromised cartilage. The consequences of a single intra-articular injection of local anesthetic remains unclear and requires further investigation.

CLINICAL RELEVANCE

Intra-articular use of local anesthetics may have lasting detrimental effects on human articular cartilage and chondrocytes, although the clinical relationship between local anesthetic exposure and chondrolysis requires further study.

Glenohumeral osteoarthritis after arthroscopic Bankart repair for anterior instability

BACKGROUND

Few data on shoulder arthropathy in patients undergoing arthroscopic repair for glenohumeral instability are available.

HYPOTHESIS

Arthroscopic stabilization of Bankart lesions does not prevent the development of postoperative glenohumeral osteoarthritis.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Clinical (Rowe and Constant scores) and radiographic preoperative and postoperative data from 60 patients who underwent arthroscopic Bankart repair were compared. Osteoarthritis was graded preoperatively and postoperatively with the Buscayret classification grading system. The average age at surgery was 27.6 years, and follow-up averaged 8.0 years.

RESULTS

The postoperative incidence of osteoarthritis in patients with no preoperative degenerative changes was 21.8% (12 of 55 patients). The incidence of degenerative joint disease of the glenohumeral joint showed evidence of a statistically significant association with older age at first dislocation and at surgery, increased length of time from the first episode to surgery, increased number of preoperative dislocations, increased length of time from the initial dislocation until surgery, increased number of anchors used at surgery, and more degenerated labrum at surgery. A higher number of preoperative dislocations, a greater length of follow-up, and reduced external rotation in abduction influenced Rowe and Constant scores.

CONCLUSION

The number of anchors used and the state of the labrum are the most important factors associated with a higher risk of radiographic degenerative changes. Longer follow-up investigations are needed to draw meaningful conclusions.

Thermal shrinkage for shoulder instability

Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent shoulder stabilization surgery with thermal capsular shrinkage using a monopolar radiofrequency device. Follow-up included a subjective outcome questionnaire, discussion of pain, instability, and activity level. Mean follow-up was 3.3 years (range 2.0-4.7 years). The thermal capsular shrinkage procedure failed due to instability and/or pain in 31% of shoulders at a mean time of 39 months. In patients with unidirectional anterior instability and those with concomitant labral repair, the procedure proved effective. Patients with multidirectional instability had moderate success. In contrast, four of five patients with isolated posterior instability failed. Thermal capsular shrinkage has been advocated for the treatment of shoulder instability, particularly mild to moderate capsular laxity. The ease of the procedure makes it attractive. However, our retrospective review revealed an overall failure rate of 31% in 80 patients with 2-year minimum follow-up. This mid- to long-term cohort study adds to the literature lacking support for thermal capsulorrhaphy in general, particularly posterior instability.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s11420-010-9187-7) contains supplementary material, which is available to authorized users.

Local infiltration analgesia

Pain after major abdominal, orthopedic, and thoracic surgeries can be significant causing unacceptable morbidity. Poorly controlled pain results in patient dissatisfaction and may also be associated with major morbidities, including perioperative myocardial ischemia, pulmonary complications, altered immune function, and postoperative cognitive dysfunction. Various techniques are currently used to manage this pain, and opioids are amongst the most frequently used. Recent literature supports the use of regional anesthesia in the form of various peripheral nerve blocks as a better alternative. This article discusses the role and evidence for wound infiltration analgesia in general surgery, orthopedic surgery, neurosurgery, and thoracic surgery.

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.

Incidence and risk of chondrolysis in Denmark: A nationwide population-based study

BACKGROUND

Chondrolysis is a rare disease with destruction of cartilage of joints. Incidence and risk factors have not been studied in a formal epidemiologic population-based setting.

METHODS

We used the Danish National Registry of Patients (NRP) covering all Danish hospitals to identify all cases of chondrolysis from 1994 to 2008. Incidence rates were estimated using the general population as the denominator. For each chondrolysis patient, 10 age-matched population controls were sampled for a case-control analysis. For cases and controls, we ascertained in the NRP history of diabetes, rheumatoid arthritis, orthopedic surgery, including surgery of shoulder and upper arm, injury to shoulder girdle or upper arm, and treatment with pain pump. We determined the prevalence of these risk factors in cases and controls, and computed odds ratios (OR).

RESULTS

We identified 43 patients with chondrolysis in the 15-year study period. The incidence rate was 5.5 per 10,000,000 person-years. Diabetes was more prevalent in chondrolysis cases, compared with the 430 controls (OR = 6.7; 95% confidence intervals [CI]: 1.1-39.9). Orthopedic surgery was also associated with an increased risk of chondrolysis (OR = 28.8, 95% CI: 11.0-75.6), while previous injury was not (OR = 0.8; 95% CI: 0.1-5.9).

CONCLUSION

Chondrolysis was rarely diagnosed in Denmark. Diabetes and orthopedic surgery may be risk factors.

Complications in shoulder arthroscopy

Shoulder arthroscopy is generally a safe and effective method for treating a wide variety of shoulder pathology. Fortunately, complications following shoulder arthroscopy are rare, with reported rates between 4.6% and 10.6%.¹⁻⁷ These rates may be underestimated, as underreporting of complications and varying definitions of the term complication are likely. During shoulder arthroscopy, complications may occur at numerous points. The surgeon must be aware of potential problems and take necessary measures to prevent them. This article describes common complications after arthroscopic shoulder surgery. Although failure of treatment and postoperative stiffness are undesirable outcomes, they are not described.

Safety of amide local anesthetics: new trends

IMPORTANCE OF THE FIELD

Local anesthetics have become one of the most common drugs used in daily practice worldwide. Neurologic and cardiovascular events are the most frequent adverse reactions related to local anesthetics use. Recently, new trends have been developed on this topic.

AREAS COVERED IN THIS REVIEW

We performed an overview of the data available so far on local anesthetics adverse reactions. Relevant literature was identified using PubMed search of articles published up to November 2009, including experimental studies, case reports or clinical studies when available. Search terms included: 'local anaesthetics', 'adverse drug reaction', 'pharmacovigilance' and 'complication'.

WHAT THE READER WILL GAIN

Neurologic, cardiovascular and allergic reactions remain the most frequent adverse drug reactions related to local anesthetics in the literature. Studies based on pharmacovigilance systems have highlighted the frequency of adverse reactions little known until now, such as failure of block. Lipid emulsions are included into algorithm for cardiac resuscitation. Recent studies have demonstrated the myotoxicity and chondrotoxic effects of long-acting local anesthetics.

TAKE HOME MESSAGE

Physicians must keep in mind all these adverse reactions to better prevent their occurrence and give the most appropriate treatment.