Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Published in
Clinical Orthopaedics and Related Research®
Volume 466 | Issue 7 | Jul, 2008

The Basic Science of Tendinopathy

Yinghua Xu MBBS, George A. C. Murrell MD, DPhil Tendinopathy is a common clinical problem with athletes and in many occupational settings. Tendinopathy can occur in any tendon, often near its insertion or enthesis where there is an area of stress concentration, and is directly related to the volume of repetitive load to which the tendon is exposed. Recent studies indicate tendinopathy is more likely to occur in situations that increase the “dose” of load to the tendon enthesis – including increased activity, weight, advancing age, and genetic factors. The cells in tendinopathic tendon are rounder, more numerous, and show evidence of oxidative damage and more apoptosis. These cells also produce a matrix that is thicker and weaker with more water, more immature and cartilage-like matrix proteins, and less organization. There is now evidence of a population of regenerating stem cells within tendon. These studies suggest prevention of tendinopathy should be directed at reducing the volume of repetitive loads to below that which induces oxidative-induced apoptosis and cartilage-like genes. The management strategies might involve agents or cells that induce tendon stem cell proliferation, repair and restoration of matrix integrity.

Treatment of Tendinopathy: What Works, What Does Not, and What is on the Horizon

Brett M. Andres MD, George A. C. Murrell MD, Dphil Tendinopathy is a broad term encompassing painful conditions occurring in and around tendons in response to overuse. Recent basic science research suggests little or no inflammation is present in these conditions. Thus, traditional treatment modalities aimed at controlling inflammation such as corticosteroid injections and nonsteroidal antiinflammatory medications (NSAIDS) may not be the most effective options. We performed a systematic review of the literature to determine the best treatment options for tendinopathy. We evaluated the effectiveness of NSAIDS, corticosteroid injections, exercise-based physical therapy, physical therapy modalities, shock wave therapy, sclerotherapy, nitric oxide patches, surgery, growth factors, and stem cell treatment. NSAIDS and corticosteroids appear to provide pain relief in the short term, but their effectiveness in the long term has not been demonstrated. We identified inconsistent results with shock wave therapy and physical therapy modalities such as ultrasound, iontophoresis and low-level laser therapy. Current data support the use of eccentric strengthening protocols, sclerotherapy, and nitric oxide patches, but larger, multicenter trials are needed to confirm the early results with these treatments. Preliminary work with growth factors and stem cells is promising, but further study is required in these fields. Surgery remains the last option due to the morbidity and inconsistent outcomes. The ideal treatment for tendinopathy remains unclear.,[object Object]

Coordinate Regulation of IL-1β and MMP-13 in Rat Tendons Following Subrupture Fatigue Damage

Hui B. Sun PhD, Yonghui Li PhD, David T. Fung PhD, Robert J. Majeska PhD, Mitchell B. Schaffler PhD, Evan L. Flatow MD Mechanical overloading is a major causative factor of tendinopathy; however, its underlying mechanisms are unclear. We hypothesized mechanical overloading would damage tendons and alter genes associated with tendinopathy in a load-dependent manner. To test this hypothesis, we fatigue loaded rat patellar tendons in vivo and measured expression of the matrix-degrading enzyme MMP-13 and the inflammatory cytokine IL-1β. We also examined these responses in cultured tenocytes exposed to intermittent hydrostatic pressure in vitro. Additionally, we hypothesized load-induced changes in tenocyte MMP-13 expression would be dependent on expression of IL-1β. In vivo fatigue loading at 1.7% strain caused overt microstructural damage and upregulated expression of MMP-13 and IL-1β, while 0.6% strain produced only minor changes in matrix microstructure and downregulated expression of both MMP-13 and IL-1β. Loading of cultured tenocytes at 2.5 and 7.5 MPa produced comparable changes in expression to those of in vivo tendon loading. Blocking IL-1β expression with siRNA suppressed load-induced both MMP-13 mRNA expression and activity. The data suggest fatigue loading alters expression of MMP-13 and IL-1β in tendons in vivo and tenocytes in vitro in a load-dependent manner. The data also suggest MMP-13 is regulated by both IL-1β-dependent and IL-1β-independent pathways.

Loss of Homeostatic Tension Induces Apoptosis in Tendon Cells: An In Vitro Study

Monika Egerbacher DVM, PhD, Steven P. Arnoczky DVM, Oscar Caballero MS, Michael Lavagnino PhD, Keri L. Gardner MS Apoptosis (programmed cell death) has been identified as a histopathologic feature of tendinopathy. While the precise mechanism(s) that triggers the apoptotic cascade in tendon cells has not been identified, it has been theorized that loss of cellular homeostatic tension following microscopic damage to individual tendon fibrils could be the stimulus for initiating the pathologic events associated with tendinopathy. To determine if loss of homeostatic tension following stress deprivation could induce apoptosis in tendon cells, rat tail tendons were stress-deprived or cyclically loaded (3% strain at 0.17 Hz) for 24 hours under tissue culture conditions. Caspase-3 (an upstream mediator of apoptosis) mRNA expression was evaluated using quantitative polymerase chain reaction and caspase-3 protein synthesis was identified using immunohistochemistry. Apoptotic cells were identified histologically using an antibody for single-stranded DNA. Stress deprivation for 24 hours resulted in an increase in caspase-3 mRNA expression when compared to fresh controls or cyclically loaded tendons. Stress deprivation also increased the percentage of apoptotic cells (10.59% ± 2.80) compared to controls (1.87% ± 1.07) or cyclically loaded tendons (3.73% ± 0.87). These data suggest loss of homeostatic tension following stress deprivation induces apoptosis in rat tail tendon cells.

Heat Shock Protein and Apoptosis in Supraspinatus Tendinopathy

Neal L. Millar MBChB, MRCS (Glasg), Ai Q. Wei MBBS, Timothy J. Molloy PhD, Fiona Bonar MBChB, MRCPI, FRCPath(Lond), George A. C. Murrell MD, DPhil Heat shock proteins (HSPs) are often upregulated following oxidative and other forms of stress. Based on reports of excessive apoptosis in torn supraspinatus tendon and mechanically loaded tendon cells, we hypothesized heat shock proteins may be present in rodent and human models of tendinopathy due to their central role in caspase dependent apoptotic cell signaling. We used a running rat supraspinatus tendinopathy overuse model with custom microarrays to investigate the process at a genetic level. Additionally torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from 10 patients undergoing arthroscopic stabilization surgery and evaluated using semiquantative RT-PCR and immunohistochemistry. We identified substantial upregulation of heat shock proteins and apoptotic genes in the rodent model. We further confirmed increased levels of heat shock protein and apoptotic regulatory genes in human supraspinatus and subscapularis tendon. This finding suggests heat shock proteins play a role in the cascade of stress-activated programmed cell death and degeneration in tendinopathy and may provide a novel target in preventing tendinopathies.

Collagens, Proteoglycans, MMP-2, MMP-9 and TIMPs in Human Achilles Tendon Rupture

Evgenia Karousou PhD, Mario Ronga MD, Davide Vigetti PhD, Alberto Passi MD, PhD, Nicola Maffulli MD, MS, PhD, FRCS(Orth) Tendon integrity depends on the extracellular matrix (ECM) metabolism which is regulated by proteolytic enzymes. However, it is unclear which enzymes play a role in tendon rupture. We studied the ECM of 19 ruptured human Achilles tendons, comparing the composition of specimens harvested close to the rupture with specimens harvested from an apparently healthy area in the same tendon. We compared gene expression of collagen Type I, decorin, and versican including enzymes involved in their metabolism as matrix metalloproteases (MMP-2 and -9) and tissue inhibitory of metalloproteinase (TIMP-1 and -2) using real-time PCR, zymography and FACE analysis. We found greater gene expression of proteoglycan core protein decorin and versican, collagen Type I, MMPs and TIMPs in the tendon rupture. Zymography analysis, reflecting expression of enzymatic activity, confirmed the gene expression data at protein level. Carbohydrate content was greater in the macroscopically healthy area than in the ruptured area. In the ruptured area, we found increased core protein synthesis but without the normal glycosaminoglycan production. The tissue in the area of rupture undergoes marked rearrangement at molecular levels and supports the role of MMPs in the pathology.

Loss of Homeostatic Strain Alters Mechanostat “Set Point” of Tendon Cells In Vitro

Steven P. Arnoczky DVM, Michael Lavagnino PhD, Monika Egerbacher DVM, PhD, Oscar Caballero MS, Keri Gardner MS, Marisa A. Shender Tendon cells respond to mechanical loads. The character (anabolic or catabolic) and sensitivity of this response is determined by the mechanostat set point of the cell, which is governed by the cytoskeleton and its interaction with the extracellular matrix. To determine if loss of cytoskeletal tension following stress deprivation decreases the mechanoresponsiveness of tendon cells, we cultured rat tail tendons under stress-deprived conditions for 48 hours and then cyclically loaded them for 24 hours at 1%, 3%, or 6% strain at 0.17 Hz. Stress deprivation upregulated MMP-13 mRNA expression and caused progressive loss of cell-matrix contact compared to fresh controls. The application of 1% strain to fresh tendons for 24 hours inhibited MMP-13 mRNA expression compared to stress-deprived tendons over the same period. However, when tendons were stress-deprived for 48 hours and then subjected to the same loading regime, the inhibition of MMP-13 mRNA expression was decreased. In stress-deprived tendons, it was necessary to increase the strain magnitude to 3% to achieve the same level of MMP-13 mRNA inhibition seen in fresh tendons exercised at 1% strain. The data suggest loss of cytoskeletal tension alters the mechanostat set point and decreases the mechanoresponsiveness of tendon cells.

VEGF Expression in Patellar Tendinopathy: A Preliminary Study

Alexander Scott MSc, BSc(PT), Øystein Lian MD, PhD, Roald Bahr MD, PhD, David A. Hart PhD, Vincent Duronio PhD Vascular function and angiogenesis are regulated by vascular endothelial growth factor-A (VEGF). The purpose of this preliminary study was to address the following questions: Is VEGF expression in the patellar tendon more prevalent in patients with patellar tendinopathy than in individuals with normal, pain-free patellar tendons? Which cell populations express VEGF in normal and tendinopathic tendon? Is there a difference in symptom duration between VEGF+ and VEGF− tendons? We collected patellar tendon tissue from 22 patients undergoing open débridement of the patellar tendon and from 10 patients undergoing intramedullary nailing of the tibia. VEGF expression was assessed immunohistochemically. Relevant inflammatory and repair cell types were immunolabeled. VEGF expression was absent from control tendons, but was present in a subset of patients with histopathological evidence of angiofibroblastic tendinosis. VEGF was expressed in the intimal layer of tendon vessels, but was absent in other cell types. Patients demonstrating VEGF expression in the patellar tendon had a shorter symptom duration (12 ± 7.8 months) than patients with no detectable VEGF (32.8 ± 23.5 months). VEGF may contribute to the vascular hyperplasia that is a cardinal feature of symptomatic tendinosis, particularly in cases with more recent onset.

Movin and Bonar Scores Assess the Same Characteristics of Tendon Histology

Nicola Maffulli MD, MS, PhD, FRCS (Orth), Umile Giuseppe Longo MD, Francesco Franceschi MD, Carla Rabitti MD, Vincenzo Denaro MD The Movin scoring system and its validated modifications and the Bonar scoring system are used to classify the histopathological findings of tendinopathy. We compared the reliability of these two different histopathological evaluation scores of tendon tissue. Tendon samples were harvested from 88 individuals (49 men, 39 women; mean age, 58.2 years) who underwent arthroscopic repair of a rotator cuff tear, and from five male patients who died of cardiovascular events (mean age, 69.6 years). A piece of supraspinatus tendon that was not directly involved in the tear was harvested en bloc within the intact middle portion of the tendon. Using hematoxylin and eosin staining and Alcian blue, slides were assessed using Bonar and Movin scores. The intraclass correlation was 0.921 (confidence interval 95% 0.790–0.963). Movin’s and Bonar’s scores have a high correlation and assess similar characteristics and variables of tendon abnormalities.

Gene Expression in Rat Supraspinatus Tendon Recovers From Overuse With Rest

Scott A. Jelinsky PhD, Spencer P. Lake BS, Joanne M. Archambault PhD, Louis J. Soslowsky PhD Rest is a common treatment for overuse injuries, but its effectiveness on gene expression has not been systematically evaluated under controlled experimental conditions. We asked whether genes regulated in the supraspinatus tendon as a result of overuse would return to normal levels after 2 or 4 weeks of rest. We used a rat model of tendon overuse that generates reproducible changes in the histology, geometry, gene expression, and mechanical properties consistent with an overuse injury. Animals were subjected to the overuse protocol for 2 or 4 weeks followed by either 2 or 4 weeks of rest. Microarray analysis was used to measure global changes in gene expression after the overuse plus rest protocol. Genes upregulated as a result of the overuse returned to near normal levels after rest in most animals. The biochemical composition of the tendon was similar to normal after the imposed rest period, except for slightly lower collagen content. These results suggest as little as 2 weeks of rest is often sufficient to recover from the molecular and biochemical effects of 2 and 4 weeks of overuse in this rat model.

Addition of Nitric Oxide Through Nitric Oxide-paracetamol Enhances Healing Rat Achilles Tendon

George A. C. Murrell MD, DPhil, Gongyao Tang MD, Richard C. Appleyard PhD, Piero Soldato MD, Min-Xia Wang MD Nitric oxide is an important messenger molecule in many physiological processes. The addition of NO via NO-flurbiprofen enhances the material properties of healing tendon, however, flurbiprofen has a detrimental effect on healing. We asked if NO delivered by a cyclooxygenase 3 inhibitor (paracetamol/acetaminophen) would enhance healing in a rat Achilles tendon healing model. Rats were injected subcutaneously daily with NO-paracetamol, paracetamol or vehicle from two days before surgery to the day of tissue harvesting. Paracetamol had no effect on tendon healing compared with vehicle alone. NO-paracetamol did not change the failure load, but did decrease the water content, enhance the collagen content, reduce the cross-sectional area and improve the ultimate stress of healing tendon compared with paracetamol and vehicle. The collagen organization of the healing tendon in the NO-paracetamol group, as determined by polarized light microscopy, was enhanced. Our data suggests NO-paracetamol increases the total collagen content and enhances organization while decreasing the cross-sectional area of healing rat Achilles tendon and is consistent with human clinical trials where NO has improved the symptoms and signs of tendinopathy.

Successful Management of Tendinopathy With Injections of the MMP-inhibitor Aprotinin

John Orchard MD, PhD, FACSP, FACSM, FFSEM (UK), Andrew Massey MB BCh BAO BSc(Hons), Richard Brown MBBS Bsc(Med) (Hons) FRACGP FACSP, Adéline Cardon-Dunbar, Jamie Hofmann MD Aprotinin is a broad spectrum proteinase inhibitor (including matrix metalloproteinase [MMP] inhibitor) used for treating patellar and Achilles tendinopathies. One previous randomized control trial demonstrated aprotinin injections superior to both corticosteroid and saline injections in patellar tendinopathy (Level II), whereas results reported for aprotinin treatment in Achilles tendinopathy have been mixed. We performed a case review and followup questionnaire for 430 consecutive patients with tendinopathy treated by 997 aprotinin injections (30,000 KIU). A response rate of 72% was achieved with a minimum followup of 3 months (average, 12.2 months; range, 3–54 months). Seventy-six percent of patients had improved, 22% of patients reported no change, and 2% were worse. Sixty-four percent of patients thought aprotinin injections were helpful, while 36% believed they had neither a positive nor negative effect. Mid-Achilles tendinopathy patients (84% improvement) were more successfully treated than patellar tendinopathy patients (69% improvement). Despite stronger published evidence of benefit in patellar tendinopathy, clinical outcomes appeared better with aprotinin use in Achilles tendinopathies.,[object Object]

Mean 20-year Followup of Bernese Periacetabular Osteotomy

Simon D. Steppacher MD, Moritz Tannast MD, Reinhold Ganz MD, Klaus A. Siebenrock MD The goal of the Bernese periacetabular osteotomy is to correct the deficient acetabular coverage in hips with developmental dysplasia to prevent secondary osteoarthrosis. We determined the 20-year survivorship of symptomatic patients treated with this procedure, determined the clinical and radiographic outcomes of the surviving hips, and identified factors predicting poor outcome. We retrospectively evaluated the first 63 patients (75 hips) who underwent periacetabular osteotomy at the institution where this technique was developed. The mean age of the patients at surgery was 29 years (range, 13–56 years), and preoperatively 24% presented with advanced grades of osteoarthritis. Four patients (five hips) were lost to followup and one patient (two hips) died. The remaining 58 patients (68 hips) were followed for a minimum of 19 years (mean, 20.4 years; range, 19–23 years) and 41 hips (60%) were preserved at last followup. The overall mean Merle d’Aubigné and Postel score decreased in comparison to the 10-year value and was similar to the preoperative score. We observed no major changes in any of the radiographic parameters during the 20-year postoperative period except the osteoarthritis score. We identified six factors predicting poor outcome: age at surgery, preoperative Merle d’Aubigné and Postel score, positive anterior impingement test, limp, osteoarthrosis grade, and the postoperative extrusion index. Periacetabular osteotomy is an effective technique for treating symptomatic developmental dysplasia of the hip and can maintain the natural hip at least 19 years in selected patients.,[object Object]

Extraarticular Fractures after Periacetabular Osteotomy

Norman Espinosa MD, Joshua Strassberg MD, Etienne L. Belzile MD, FRCS(C), Michael B. Millis MD, Young-Jo Kim MD, PhD Extraarticular fractures of the pelvic ring after periacetabular osteotomy could impair stability of the acetabular fragment and cause poor clinical and radiographic outcomes. We evaluated 17 patients (17 hips) with fractures of either the ipsilateral os pubis (n = 12) or os ischium (n = 5) during the postoperative period after periacetabular osteotomy. Ischial fractures seemed more debilitating with two of five resulting in painful nonunions for which additional surgery was performed. In contrast, only one patient with pubic fracture had additional surgery. Ischial fractures took almost twice as long to achieve resolution of symptoms compared with pubic fractures, and when left untreated, asymptomatic nonunions developed in three of five. However, we observed no effect on acetabular fragment positioning or long-term clinical outcome. It is essential to be aware of this potential complication and realize it could be accompanied by substantial morbidity for patients during the rehabilitation period after periacetabular osteotomy, but does not seem to influence the longer-term outcome.,[object Object]

Risk factors for Periprosthetic Fractures of the Hip: A Survivorship Analysis

R. E. Cook FRCSEd (Orth), P. J. Jenkins MRCS(Ed), P. J. Walmsley MRCS(Ed), J. T. Patton FRCSEd (Orth), C. M. Robinson BMedSci, FRCSEd (Orth) Periprosthetic fracture is an uncommon but typically complex complication of cemented THA usually treated operatively. It is a source of reduced function, subsequent morbidity, and increased mortality. Previous studies may have underestimated the incidence of fracture through loss to followup or failure to use survivorship methodologies. The primary aim of this study was to use survivorship methodology to investigate the incidence of, and risk factors for fracture following primary arthroplasty. We examined a cohort of 6458 primary cemented femoral prostheses implanted during a 17-year period. One hundred twenty-four patients sustained fractures at the tip or below the femoral prosthesis. The incidence of fracture was 0.8% at 5 years and 3.5% at 10 years after primary implant. Patients older than 70 years had a 2.9 times greater risk of sustaining a subsequent fracture. There was no association between fracture and gender or implant type. These rates are higher than those reported for cemented arthroplasties. Older patients should be counseled regarding their higher risk of periprosthetic fracture, and additional research is required to elucidate the biologic mechanisms involved.,[object Object]

Acetabular Cage Survival and Analysis of Factors Related to Failure

Jonathan N. Sembrano MD, Edward Y. Cheng MD The reported results of acetabular cage reconstruction for pelvic deficiency are widely variable. Our primary question was: what is the survivorship of cage reconstruction with a primary end point of cage revision and secondary end points of radiographic loosening and any reoperation? Secondary questions were: which factors predict cage failure, and what is the functional outcome (SF-36, WOMAC, Harris hip score) of this reconstructive method? We reviewed 72 cage reconstructions in 68 patients. Minimum followup was 1.2 years (mean, 5.1 years; range, 1.2–10.7 years). Five-year cage revision-free survivorship was 87.8%. Five-year loosening-free and acetabular reoperation-free survivorships were 80.7% and 81.3%, respectively. No single preoperative factor (age, gender, severity of pelvic defect, degree of heterotopic ossification, difference in limb lengths and centers of rotation) or intraoperative factor (type of bone graft, type of cage, changes in limb length and center of rotation) predicted cage failure. Functional outcomes were 28.9 (SF-36 Physical Component), 52.4 (SF-36 Mental Component), 33.7 (WOMAC), and 44.2 (Harris). We judged these outcomes acceptable for this sometimes challenging problem. Future techniques for treating pelvic deficiency will need to be compared with these and other outcomes in the literature.,[object Object]

Registry Outcomes of Unicompartmental Knee Arthroplasty Revisions

Thomas E. Dudley MD, PhD, Terence J. Gioe MD, Penny Sinner MPH, Susan Mehle BS Perceptions of the difficulty and outcome of unicompartmental knee arthroplasty revision (rev-UKA) vary. We analyzed differences in the complexity, cost, and survival of rev-UKAs compared with revision TKAs (rev-TKA). One hundred eighty knee arthroplasty revisions (68 rev-UKAs/112 rev-TKAs), defined as a minimum of tibial or femoral component revision, were identified from a community joint registry of 7587 knee implants performed between 1991 and 2005. Four of 68 rev-UKAs (5.9%) were revised a second time, whereas seven of 112 rev-TKAs (6.3%) were rerevised. Rev-TKA was predictably more complex than rev-UKA based on the proxies of operative time, use of modular augmentation and stems, and polyethylene liner thickness. Thirty-nine of 68 rev-UKAs (57%) had no form of augmentation and were revised as primary TKAs. There were more rev-TKAs than rev-UKAs with an implant cost greater than $5200 (42% versus 12%) and hospital charges greater than $33,000 (48% versus 25%). We found no difference in survival between the groups. Although rev-UKAs had less surgical complexity and bone loss at the time of revision compared with rev-TKAs, we were unable to show improved survival of rev-UKAs compared with rev-TKAs. Rev-UKAs were associated with lower implant costs and hospital charges compared with rev-TKAs.,[object Object]

Lateral Femoral Epicondylar Osteotomy: An Extensile Posterolateral Knee Approach

Andrea L. Bowers MD, G. Russell Huffman MD, MPH Open exposure of the posterolateral corner of the knee is challenged by limitations of posterolateral ligamentous tissues and posterior neurovascular structures. We have used a modification of a lateral femoral epicondyle osteotomy, described historically for surgical management of posterolateral rotatory instability, as an approach to the posterolateral intraarticular structures. The historic technique for ligamentous reconstruction has been abandoned because its nonanatomic fixation does not restore ligamentous isometry. In this report, osteotomy of a bone block from the lateral femoral epicondyle is used to access the joint space. The lateral collateral ligament is reflected distally and posteriorly through traction on the block. Once the intraarticular disorder has been addressed, the lateral femoral epicondyle is secured in its native, anatomic position, thereby restoring isometry and normal joint mechanics after surgery. This technique has been used successfully to address posterolateral articular disorders on femoral and tibial sides. Postoperative magnetic resonance imaging verified restoration of lateral collateral ligament anatomy. Physical examination at 0° and 30° knee flexion showed clinical stability at all postoperative evaluations through 6 and 10 months followup. Using this technique, intraarticular disorders at the posterolateral corner may be addressed in an open manner with anatomic reduction and preserved postoperative function of the lateral collateral ligament.,[object Object]

Surgery for Retrocalcaneal Bursitis: A Tendon-splitting versus a Lateral Approach

John A. Anderson MD, MRCS, Eduardo Suero MD, Padhraig F. O’Loughlin MD, John G. Kennedy MD, FRCS(Orth) For patients with refractory retrocalcaneal bursitis (Haglund’s syndrome), the most effective surgical approach has not been defined. We asked whether patients undergoing the tendon-splitting approach and the lateral approach would have comparably effective relief of pain for both types of calcaneal ostectomies. We retrospectively reviewed 30 patients (31 feet) who underwent the tendon-splitting approach and compared their results with 32 previous patients (35 feet) who had a lateral incision. Minimum followup was 12 months (mean, 16 months; range, 12–23 months) for the tendon-splitting group and 15 months (mean, 51 months; range, 15–109 months) for the lateral group. The mean American Orthopaedic Foot and Ankle Society score improved from 43 points preoperatively to 81 points (range, 8–100 points) postoperatively in the tendon-splitting group and from 54 points to 86 points (range, 55–100 points) in the lateral group. The mean physical component score of the Short Form-36, version 2, at followup was 52 (range, 22–61) in the tendon-splitting group and 49 (range, 34–63) in the lateral group. The median return to normal function was 4.1 months (range, 3–13 months) in the tendon-splitting group and 6.4 months (range, 4–20 months) in the lateral group. Both approaches to calcaneal ostectomy provided symptomatic pain relief. However, patients in the tendon-splitting group returned to normal function quicker than patients in the lateral group.,[object Object]

Surgery Can Reduce the Nonoperative Care Associated with an Equinovarus Foot Deformity

Sudheer Reddy MD, Sharat Kusuma MD, MBA, Harish Hosalkar MD, MBMS, (Orth), FCPS (Orth), DNB (Orth), Mary Ann Keenan MD Equinovarus is the most common lower extremity deformity seen after a stroke. Despite its frequency, there are no specific guidelines in determining when surgery should be considered and for which patients it is appropriate. We evaluated the charges of nonsurgical and surgical treatments for equinovarus foot in 29 consecutive patients who underwent surgery for a unilateral equinovarus deformity after stroke. Twenty-six patients (seven males, 19 females) were available for followup. Mean patient age at the time of stroke was 48.2 years (range, 3–66 years). The average age at surgery was 54.7 years (range, 23–72 years), with a mean duration of nonsurgical treatment of 74.7 months. The minimum followup was 6 months following surgery (mean, 18.2 months; range, 6–48 months). Physical therapy accounted for 88% of nonoperative charges, with chemodenervation and orthotics accounting for 10% and 2%, respectively. Postoperatively, 19 patients were able to discontinue physical therapy compared with none preoperatively, and 17 discontinued orthotic use. Surgical correction of the equinovarus foot, in the appropriate patient, can decrease the use of nonoperative care for a patient who has had a stroke. We recommend surgery be considered earlier when an equinovarus deformity persists after the period of spontaneous neurologic recovery.,[object Object]

Acetabular Changes in Coxa Vara

Ashish Ranade MD, James J. McCarthy MD, Richard S. Davidson MD The purpose of this study was to define the acetabular changes associated with coxa vara and determine how these acetabuli differ from those of a normal hip. Charts and radiographs of 33 patients with coxa vara with a mean age of 6 years (range, 2–15 years) were retrospectively reviewed. The diagnosis was developmental coxa vara in 21 patients and congenital femoral deficiency in 12. Radiographic measurements, including acetabular index, sourcil slope, center edge angle, migration index, and medial joint space, were compared with those of 29 hips in the control group. The inclination of the acetabulum or acetabular slope (as measured by the acetabular index and sourcil slope) was significantly increased in the hips with coxa vara as compared with those in the control group. Both parameters have a statistically significant inverse correlation with the degree of varus, ie, the greater the varus of the proximal femur, the greater the upsloping of the acetabulum. Joint subluxation, as measured by the center edge angle, migration index, and medial joint space, showed little difference from that of control subjects.,[object Object]

High Association of Posterior Malleolus Fractures with Spiral Distal Tibial Fractures

Sreevathsa Boraiah MD, Michael J. Gardner MD, David L. Helfet MD, Dean G. Lorich MD Associations between fracture patterns are important and can ensure proper diagnosis and guide treatment. Occult posterior malleolus fractures associated with distal spiral tibia fractures often are underrecognized and the morbidity of a missed posterior malleolus injury can be substantial. We determined the association between the two injuries and evaluated the ability of a new protocol to improve management of these associated fractures. Of 62 consecutive patients with fractures of the distal third of the tibia, we retrospectively evaluated the first 39 patients and prospectively used a diagnostic protocol including computed tomography of the ankle in the subsequent 23 patients. The minimum followup was 3 months (mean, 25 months; range, 3–68 months). Twenty-four patients (39%) had fractures of the posterior malleolus. Before initiation of the protocol, intraarticular fractures were recognized in 33% (with one delayed diagnosis and one missed diagnosis), and after institution of the protocol, the detection rate was 48% with no known missed injuries and complete followup; however, with the limited power the detection rates were similar without and with the protocol. A spiral distal tibial shaft fracture with a proximal fibula fracture should alert the surgeon to investigate an occult ankle injury, particularly of the posterior malleolus. A protocol including computed tomography of the ankle may detect more injuries in a larger study.,[object Object]

Chitosan-coated Stainless Steel Screws for Fixation in Contaminated Fractures

Alex H. Greene BS, Joel D. Bumgardner PhD, Yunzhi Yang PhD, Jon Moseley PhD, Warren O. Haggard PhD Stainless steel screws and other internal fixation devices are used routinely to stabilize bacteria-contaminated bone fractures from multiple injury mechanisms. In this preliminary study, we hypothesize that a chitosan coating either unloaded or loaded with an antibiotic, gentamicin, could lessen or prevent these devices from becoming an initial nidus for infection. The questions investigated for this hypothesis were: (1) how much of the sterilized coating remains on the screw with simulated functional use; (2) is the unloaded or loaded chitosan coating bacteriostatic and biocompatible; and (3) what amount and rate does an antibiotic elute from the coating? In this study, the gentamicin eluted from the coating at a detectable level during 72 to 96 hours. The coating was retained at the 90% level in simulated bone screw fixation and the unloaded and loaded chitosan coatings had encouraging in vitro biocompatibility with fibroblasts and stem cells and were bacteriostatic against at least one strain of Staphylococcus aureus. The use of an antibiotic-loaded chitosan coating on stainless steel bone screws and internal fixation devices in contaminated bone fracture fixation may be considered after optimization of antibiotic loading and elution and more expanded in vitro and in vivo investigations with other organisms and antibiotics.

Galeazzi Lesions in Children and Adolescents: Treatment and Outcome

Robert Eberl MD, Georg Singer MD, Johannes Schalamon MD, Thomas Petnehazy MD, Michael E. Hoellwarth MD A Galeazzi fracture is defined as a fracture of the radius associated with dislocation of the distal radioulnar joint. Treatment in children and adolescents is usually possible with closed reduction and casting. The objective of this retrospectively designed study was to describe all Galeazzi lesions treated at our department during a 3-year period. One hundred ninety-eight patients with displaced fractures of the radius alone or both bones of the forearm were reviewed. In 26 (13%) cases, a Galeazzi lesion was found and these patients formed the study group. Outcome was assessed using the Gartland-Werley score. Eight of 26 (31%) fractures were recognized initially and classified as a Galeazzi lesion. Casting after fracture reduction was possible in 22 patients. Thirteen patients were treated with immobilization in a below-elbow cast and nine with an above-elbow cast. Four patients were treated operatively. The results were excellent in 23 cases and good in three cases. In cases of distal forearm fractures, a possible Galeazzi lesion should be considered. However, proper reduction of the radius with concomitant reduction of the distal radioulnar joint and cast immobilization provides good to excellent outcome even if the Galeazzi lesion is primarily not recognized.,[object Object]

Periprosthetic Joint Infection: The Incidence, Timing, and Predisposing Factors

Luis Pulido MD, Elie Ghanem MD, Ashish Joshi MD, MPH, James J. Purtill MD, Javad Parvizi MD, FRCS Periprosthetic joint infection is one of the most challenging complications of joint arthroplasty. We identified current risk factors of periprosthetic joint infection after modern joint arthroplasty, and determined the incidence and timing of periprosthetic joint infection. We reviewed prospectively collected data from our database on 9245 patients undergoing primary hip or knee arthroplasty between January 2001 and April 2006. Periprosthetic joint infections developed in 63 patients (0.7%). Sixty-five percent of periprosthetic joint infections developed within the first year of the index arthroplasty. The infecting organism was isolated in 57 of 63 cases (91%). The most common organisms identified were Staphylococcus aureus and Staphylococcus epidermidis. We identified the following independent predictors for periprosthetic joint infection: higher American Society of Anesthesiologists score, morbid obesity, bilateral arthroplasty, knee arthroplasty, allogenic transfusion, postoperative atrial fibrillation, myocardial infarction, urinary tract infection, and longer hospitalization. This study confirmed some previously implicated factors and identified new variables that predispose patients to periprosthetic joint infection.,[object Object]

Molecular Identification of Bacteria from Aseptically Loose Implants

Naomi Kobayashi MD, PhD, Gary W. Procop MD, Viktor Krebs MD, Hideo Kobayashi MD, PhD, Thomas W. Bauer MD, PhD Polymerase chain reaction (PCR) assays have been used to detect bacteria adherent to failed orthopaedic implants, but some PCR assays have had problems with probable false-positive results. We used a combination of a Staphylococcus species-specific PCR and a universal PCR followed by DNA sequencing to identify bacteria on implants retrieved from 52 patients (92 implants) at revision arthroplasty. We addressed two questions in this study: (1) Is this method able to show the existence of bacterial DNA on presumed aseptic loosed implants?; and (2) What proportion of presumed aseptic or culture-negative implants was positive for bacterial DNA by PCR? Fourteen implants (15%) were believed infected, whereas 74 implants (85%) were believed aseptic. Each implant was sonicated and the resulting solution was submitted for dual real-time PCR assay and culture. All implants believed aseptically loose were culture-negative, but nine of the 74 (12%) had bacterial DNA by PCR; two (2.7%) were PCR-positive and also showed histologic findings suggestive of infection. Uniquely developed PCR and bacterial sequencing assays showed bacterial DNA on 12% of implants removed for presumed aseptic loosening. Additional studies are needed to determine the clinical importance of bacterial DNA detected by PCR but not by conventional culture.,[object Object]

Photodynamic Therapy with ATX-S10·Na(II) Inhibits Synovial Sarcoma Cell Growth

Ken Takeda MD, Toshiyuki Kunisada MD, PhD, Shinichi Miyazawa MD, PhD, Yoshinori Nakae, Toshifumi Ozaki MD, PhD Photodynamic therapy (PDT) is an effective cancer treatment modality that allows selective destruction of malignant tumor cells. We asked whether PDT could inhibit in vivo and in vitro growth of synovial sarcoma cells. We analyzed PDT using ATX-S10·Na(II) and a diode laser for a synovial sarcoma cell line (SYO-1). Photodynamic therapy with ATX-S10·Na(II) showed an in vitro cytotoxic effect on the cultured SYO-1 cells. The in vitro effect of PDT depended on the treatment concentration of ATX-S10·Na(II) and the laser dose of irradiation. ATX-S10·Na(II) was detected in the tumor tissue specimens that were excised from nude mice bearing SYO-1 within 6 hours after intravenous injection, but it was eliminated from the tumor 12 hours after injection. Photodynamic therapy suppressed the tumor growth of nude mice bearing SYO-1, and high-dose irradiation induced no viable tumor cells in histologic specimens. Photodynamic therapy performed after marginal resection of the tumor of nude mice bearing SYO-1 reduced the rate of local recurrence of the tumor. Our results suggest PDT using ATX-S10·Na(II) and laser irradiation may be a potentially useful treatment for synovial sarcoma, especially to reduce the surgical margin and preserve critical anatomic structures adjacent to the tumor.

Orthopaedic Surgeons Prefer to Participate in Expertise-based Randomized Trials

Elzbieta Bednarska BHSc (Hon), Dianne Bryant MSc, PhD, P. J. Devereaux MD, PhD, FRCPC Empiric data and theoretical arguments suggest an alternative randomized clinical trial (RCT) design, called expertise-based RCT, has enhanced validity, applicability, and ethical integrity compared with conventional RCT. Little is known, however, about whether physicians will participate in an expertise-based RCT. In a cross-sectional survey of Canadian orthopaedic surgeons, we evaluated preference for and willingness to participate in an expertise-based versus a conventional RCT if given the opportunity to participate in a trial investigating the effectiveness of high tibial osteotomy versus unicompartmental knee arthroplasty. Using an electronic survey (©2005, we invited all 767 members of the Canadian Orthopaedic Association (2005) to participate; 276 surgeons completed the questionnaire (37.5% response rate). One hundred two surgeons (53.4%) were willing to participate in an expertise-based RCT compared with 35 surgeons (18.3%) willing to participate in a conventional RCT. Ninety-seven surgeons (52.4%) strongly or moderately preferred the expertise-based design compared with 25 (13.5%) who preferred the conventional design. For the clinical example we presented, the majority of Canadian orthopaedic surgeons were willing to participate in and preferred the expertise-based design. The expertise-based randomized clinical trial design may overcome some of the barriers to conducting clinical trials in orthopaedic surgery and improve the validity of their conclusions.

Case Report

Philipp Kobbe MD, Boris A. Zelle MD, Garry S. Gruen MD Piriformis syndrome is an uncommon condition characterized by sciatic nerve entrapment at the greater sciatic notch. Nonoperative treatment such as physical therapy, nonsteroidal antiinflammatory drugs, and local injections often results in relief of symptoms. For patients who do not benefit from nonoperative therapy, surgical exploration and decompression of the sciatic nerve has been effective. However, the success of surgery may be diminished by scar formation or hematoma in the anatomically restricted sciatic notch. We report two patients with piriformis syndrome who responded primarily to surgical decompression and had recurrent symptoms resulting from scar tissue formation in the sciatic notch. On revision surgery, polytetrafluoroethylene pledgets were placed around the sciatic nerve to avoid compression and entrapment by scar tissue. Both patients had satisfactory outcomes at 3 years followup.

Protecting a Patellar Ligament Reconstruction after Proximal Tibial Resection: A Simplified Approach

Vijay Titus MS (Orth), Dip Orth, Mark Clayer MD, MBBS, FRACS, FAOrthA Limb salvage in tumor surgery has encouraged the development of megaprostheses. However, reattaching the ligamentum patellae poses a particular problem: avulsion and/or extensor lag may lead to poor function. We describe a new technique of patellar ligament reconstruction. The technique involves reattachment of the patellar ligament to the tibial tuberosity of the proximal tibial megaprosthesis, which has a porous surface created, and the repair is protected with a cerclage wire through the patella and the prosthesis. In 10 consecutive patients, the range of motion averaged 95° (median, 90°; range, 70°–120°), and the mean extension lag averaged 4° (median, 0°; range, 0°–20°). We had one case of patellar ligament avulsion. This technique resulted in good quadriceps function and a low incidence of complications.,[object Object]

Thigh Mass in a 73-year-old Man

Frank Pompo MD, Joseph J. King MD, O. Hans Iwenofu MD, Christian M. Ogilvie MD
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