Infection risk assessment in patients undergoing primary total knee arthroplasty.

PURPOSE: To determine the incidence and to identify potential risk factors for in-hospital and late infections, as well as for deep periprosthetic joint infection (PJI) following TKA. METHODS: We identified 17,959 patients treated with primary TKA between 2000 and 2009. We recorded patient demographics, comorbidities and in-hospital complications. The rates of in-hospital, late, and deep PJIs were determined. Different logistic regression models were built to identify risk factors for each of the above types of infection. RESULTS: The rates for in-hospital, post-discharge, and deep PJI were 0.65%, 0.41%, and 0.26%, respectively. Younger age, allogeneic blood transfusion, liver disease, and unilateral or staged bilateral TKA were risk factors for in-hospital infection. Renal and pulmonary disease, urinary tract infection, wound dehiscence, and prior in-hospital infection were risk factors for post-discharge infection. Male gender, history of in-hospital infection, prolonged length of stay, and pulmonary disease were identified as risk factors for deep PJI. CONCLUSION: Despite low infection rates after primary TKA, there are patients at higher risk that would benefit by addressing modifiable risk factors for both in-hospital or post-discharge infections, including deep PJIs.

Two-Stage Revision Protocol in Multidrug Resistant Periprosthetic Infection Following Total Hip Arthroplasty Using a Long Interval Between Stages.

We retrospectively reviewed the medical records of 31 patients with periprosthetic hip infections attempting to evaluate the outcome of a two-stage revision protocol characterized by prolonged interim period (mean=9.2 months, range 8-12 months) prior to the final re-implantation. In 3 cases (9.6%) the 1st stage was repeated after a mean period of 12.3 weeks due to relapse of infection. Five spacer dislocations occurred, not affecting the final clinical outcome after reimplantation, as evaluated by the Harris Hip Score. No protrusions or additional acetabular bone loss was noticed. Our proposed protocol is a simple, safe, efficient and reproducible treatment approach that may be successfully utilized predominantly when dealing with multidrug resistant pathogens.

Risk Factors for Recurrence of Periprosthetic Knee Infection.

We retrospectively reviewed 110 patients who underwent two-stage revision surgery in order to identify potential risk factors for recurrence of periprosthetic infection. We found that patients with inflammatory arthritis (P=0.0125), perioperative hematoma formation (P=0.0422), wound dehiscence (P=0.042), and those who are chronic Staphylococcus carriers (P=0.0177) were associated with an increased incidence of re-infection. The duration of intravenous antibiotic therapy less than 6 weeks was associated with a reduced risk of reinfection to greater than 6 weeks (P=0.03). Multivariate analysis indicated that wound dehiscence (odds ratio [OR], 5.119; 95% confidence interval [CI], 1.367-19.17), and Staphylococcus carriers (OR, 11.419; 95% CI, 1.376-94.727) are significant predictors of recurrence (P=0.0153 and 0.0241, respectively).

Irrigation and debridement for periprosthetic infections of the hip and factors determining outcome.

PURPOSE: Our purpose was to identify the success rate and factors predicting outcome of irrigation and debridement (I&D) in patients with deep periprosthetic joint infection (PJI) of the hip. METHODS: We retrospectively reviewed clinical characteristics of patients with deep PJI after primary/revision total hip arthroplasty (THA) between January 2000 and May 2013 treated with I&D. Implant retention was the outcome of interest. Sixty patients (29 men and 31 women; mean age 64.9 years) were identified. Mean follow-up was 59 months (range, 12-168). RESULTS: The implants were retained in 42 patients (70%). Failure of I&D treatment correlated with duration of symptoms >five days (p <0.001) and obesity [body mass index (BMI) ≥ 30)] (p = 0.0289). Treatment outcome was affected by the type of pathogen (p = 0.0482), with patients with methicillin-resistant staphylococci having significantly lower odds of success. CONCLUSIONS: I&D can be a feasible option in THA patients presenting with acute deep PJI. Duration of symptoms >five days, isolation of methicillin-resistant staphylococci and obesity should be taken into consideration in pre-operative decision making.

Reconstruction of multiple myeloma lesions around the pelvis and acetabulum.

Multiple myeloma is a malignancy of monoclonal plasma cells (plasma cells are of B-lymphocyte lineage of the hematopoietic system). It is the second most prevalent blood malignancy after non-Hodgkin's lymphoma. It accounts for approximately 1 % of all malignancies and 2 % of all cancer deaths. Bony involvement is very common; the incidence of pelvic and periacetabular involvement in MM is reported to be around 6 %. Lytic lesions comprise a hallmark of multiple myeloma, which may be complicated with pathologic fractures in a substantial percentage of patients. Pelvic and periacetabular bony involvement of multiple myeloma is associated with some unique characteristics regarding the biomechanics of this specific anatomical region, the morbidity, the overall survival, and prognosis, which all reflect to impairment of quality of life. In this paper, we review the special features of multiple myeloma lesions around the pelvis and acetabulum and present an algorithm of management with the use of current surgical techniques.

Late diagnosis of perforation of the aorta by a pedicle screw.

Although the clinical and biomechanical advantages of pedicle screws are well documented, the accuracy of their insertion is always a concern.Injury of neurovascular structures could be devastating. Perforation of the aorta from posteriorly placed screws is fortunately rare but could end up being lethal. We present a review of the current literature along with two illustrative cases with aorta perforation from posterior pedicle screws. An 82-year-old female with a history of thoracic kyphosis and a 26-year-old female with scoliotic deformity were referred to our institution owing to back pain. Both patients had undergone correction of their deformities and posterior fixation using posterior pedicle screws and rods 5 years previously. During the diagnostic work-up, which included CT scans, we incidentally found one pedicle screw to be malpositioned, exiting the vertebral body and perforating the aorta. The patients were offered a combined orthopaedic and vascular procedure, including screw removal and endovascular stenting of the aorta. Potential complications from the presence of a screw inside the pulsatile aorta, and the complexity of revision surgery should be well considered before proceeding to such a difficult surgical procedure. Systemic postoperative follow-up imaging and safer intraoperative practices during screw placement are important.

Analysis of kidney dysfunction in orthopaedic patients.

BACKGROUND: This retrospective study was undertaken to determine the incidence of kidney dysfunction (KD) and to identify potential risk factors contributing to development of KD in orthopaedic population following an elective or emergency surgery. METHODS: A total of 1025 patients were admitted in our institution over a period of one year with various indications. Eight hundred and ninety-three patients (87.1%) had a surgical procedure. There were 42 (52.5%) male and 38 (47.5%) female with a mean age of 72 years (range: 47 to 87 years). We evaluated the following potential risk factors: age, comorbidities, shock, hypotension, heart failure, medications (antibiotics, NSAIDs, opiates), rhabdomyolysis, imaging contrast agents and pre-existing KD. RESULTS: The overall incidence of KD was 8.9%. Sixty-eight patients developed acute renal injury (AKI) and 12 patients developed acute on chronic kidney disease (CKD). In sixty-six (82.5%) patients renal function was reversed to initial preoperative status. Perioperative dehydration (p = 0.002), history of diabetes mellitus (p = 0.003), pre-existing KD (p = 0.004), perioperative shock (p = 0.021) and administration of non-steroid anti-inflammatory drugs (NSAIDs) (p = 0.028) or nephrotoxic antibiotics (p = 0.037) were statistically significantly correlated with the development of postoperative KD and failure to gain the preoperative renal function. CONCLUSION: We conclude that every patient with risk factor for postoperative KD should be under closed evaluation and monitoring.

Results of extra-articular subtalar arthrodesis in children with cerebral palsy.

BACKGROUND: Grice-Green extra-articular subtalar arthrodesis is considered to be a valid surgical method which improves foot alignment in patients with spastic pes planovalgus deformity. The purpose of the present study was to examine the long-term results of Grice-Green procedure and whether it can achieve significant correction of each of the components of pes planovalgus deformity. METHODS: Eleven children (16 feet) with cerebral palsy who underwent Grice extra-articular subtalar arthrodesis were reviewed retrospectively. The mean age of patients at the time of surgery was 9 years and 8 months (range, 6 years 5 months to 12 years 4 months). The mean followup was 3 years and 7 months (range, 2 years 1 month to 8 years 3 months). Seven radiographic parameters of each patient before surgery, after surgery and at the latest followup were used. In addition, position of the graft relative to the weightbearing axis of the tibia was evaluated. RESULTS: Most of the examined parameters showed statistically significant correction which was maintained in the long run. Moreover, the placement of the graft along the mechanical axis seemed to play an important role for stability and preservation of correction of the planovalgus deformity. On the other hand, there were three cases where the osseous graft was absorbed and two cases where triple arthrodesis was necessary due to recurrence of the deformity. CONCLUSION: Grice-Green extra-articular subtalar arthrodesis improves foot alignment in patients with spastic pes planovalgus deformity and can achieve significant correction, postoperatively as well as on a long-term basis, of each of the components of pes planovalgus deformity.

Osteosarcoma invasion of the inferior vena cava and right atrium.

We present a woman with chondroblastic osteosarcoma of the left ilium extending to the L4 epidural space and invading the inferior vena cava and right atrium, misdiagnosed as deep venous thrombosis. After neoadjuvant chemotherapy, two stage resection was planned. During the anterior approach, a mass in the left common iliac vein and inferior vena cava was found and tumor thromboembolism was diagnosed. Frozen sections showed chondroblastic osteosarcoma. The patient denied further surgery and had palliative intensity modulated radiation therapy.

Comparison of four reconstructive methods for diaphyseal defects of the humerus after tumor resection.

The objective of the current study was to compare quantitative data on the biomechanical analysis of different techniques for fixation of intercalary bone defects of the humerus, by means of consistently applied methodology on composite models. A total of 25 humeral specimens of composite models were used. An intercalary defect was created and reconstructed using plates, intramedullary nails, external fixators and segmental prosthetic implants. The specimens were loaded under axial compression, four-point bending and torsion within the linear elastic region. Modular segmental implants and intramedullary nails were able to compensate significantly greater amounts of compressive loads compared to locking plates and external fixators. However, in flexion and torsion, the modular segmental implants and the external fixators were significantly better load-bearing devices compared to the intramedullary nails and plates. Early mobilization of the upper limb in patients with diaphyseal bone defects of the humerus could probably be more safe and tolerable when reconstructed with modular segmental implants.

Osteosarcoma of navicular bone. En bloc excision and salvage of the foot.

AIM: To present foot salvage for osteosarcoma of the navicular bone with en bloc resection and reconstruction using bone allograft and talus-cuneiform arthrodesis. PATIENT AND SURGICAL TECHNIQUE: A 20 year-old male with a history of osteosarcoma of the distal femur presented to our department 5 years later with a metastatic lesion of the navicular bone of the contralateral foot. The patient received 4 cycles of neo-adjuvant chemotherapy with satisfactory response. Tumor shrinkage allowed en bloc excision of the navicular bone with clear margins. Reconstruction was done using a tricortical allograft and talus-allograft-cuneiform arthrodesis, secured with a mini-fracture plate (Synthes). Weight bearing protection was advised for 2 months and partial weight bearing for another 4 months. Patient received 4 cycles of adjuvant chemotherapy. RESULTS: Three years postoperatively, the patient was free of local recurrence or distant metastasis. There were no signs of allograft resorption, fracture or non union. The patient was asymptomatic and full weight bearing. Ankle and subtalar joint motion was within normal limits. CONCLUSION: Foot salvage after excision of osteosarcoma of the navicular bone could be possible if en bloc resection of the lesion could be performed. Talus-cuneiform fusion with allograft interposition is a viable reconstructive option.

Low-Dose Perioperative Corticosteroids Can Be Administered Without Additional Morbidity in Patients Undergoing Bilateral Total Knee Replacement: A Retrospective Follow-up Study of a Randomized Controlled Trial.

Background: Short-term benefits of perioperative corticosteroid injections (CSIs) for bilateral total knee replacement (BTKR) include suppressed inflammation, improved knee motion, and reduced pain. Very little is known about the long-term benefits, complications, and safety of corticosteroids administered in the perioperative period. Purpose: We sought to compare 3-year follow-up outcomes of BTKR patients who received perioperative CSI with those who received placebo. We hypothesized that there would be no statistically significant differences in functional outcomes or adverse events based on whether or not CSIs were administered in the perioperative period. Methods: We conducted a retrospective review of chart and registry data of BTKR patients from a prior randomized controlled trial to compare outcomes in patients who received hydrocortisone vs placebo injections after BTKR (ClinicalTrials.gov: NCT01399268 and NCT01815918). Outcomes were compared at 6 and 12 weeks and at 1, 2, and 3 years. The Knee Injury and Osteoarthritis Outcome Scores (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate clinical outcomes. Cochran-Mantel-Haenszel tests were used to compare the risk of complications between treatments after adjustment for trial. When possible, summary relative risk estimates were calculated using the Mantel-Haenszel method. Results: No BTKR patients in the treatment group developed an infection. The risk of complications did not increase in patients who received CSI compared with those who received placebo. Patients in the CSI group experienced greater reductions in pain and stiffness, though these results were not statistically significant. There were no statistically significant differences in the KOOS-Symptoms, KOOS-Activities of Daily Living, KOOS-Sports, KOOS-Quality of Life, or WOMAC Function scores. Conclusions: Low-dose corticosteroids can be administered in selected patients who undergo BTKR without increasing the risk of adverse events. At 3-year follow-up, administration of low-dose corticosteroids did not result in superior clinical outcomes scores when compared with placebo.

Negative-pressure wound therapy for musculoskeletal tumor surgery.

OBJECTIVE: To evaluate the effect of negative-pressure wound therapy in musculoskeletal tumor surgery patients. MATERIALS AND METHODS: The authors analyzed the medical records of 32 patients treated at the authors' institution for bone and soft-tissue sarcomas and secondary wound-healing complications, from 2005 to 2008; there were 11 men and 21 women, with a mean age of 56 years (range, 35-72 years). RESULTS: A statistically significant difference (P = .036) was found regarding the length of hospitalization in the conventional wound treatment group, group A (mean, 25.2 days; range, 15-52 days), compared with the negative wound pressure therapy group, group B (mean, 16.5 days; range, 12-33 days). CONCLUSIONS: The use of negative-pressure wound therapy for the management of complicated wound healing in sarcoma patients following tumor surgery is safe and effective and is associated with lower overall complications rates, infection rate, and the need for further surgery and a lower total cost of wound-healing treatment.

Total scapulectomy and constrained reverse total shoulder reconstruction for a Ewing's sarcoma.

BACKGROUND: Total scapulectomy and intra-articular resection of the glenohumeral joint indicates the Malawer Type III shoulder girdle resection. MATERIALS AND METHODS: The modified Tikhoff-Linberg total scapulectomy and constrained reverse total shoulder reconstruction for a Ewing's sarcoma of the scapula is presented. A combined approach has been used. The deltoid, trapezius, rhomboids, levator scapulae, latissimus dorsi, and serratus anterior were preserved. the tumor was removed en bloc by disarticulation of the acromioclavicular and the glenohumeral joints. The scapular prosthesis was suspended by the muscles. A constrained reverse humeral prosthesis was implanted after osteotomy of the humeral head. RESULTS: There were no intraoperative or postoperative complications; surgical margins were clear. At 12 months postoperatively, the patient has a stable and painless shoulder. CONCLUSION: The goal of shoulder reconstructions is to provide a stable and painless joint that allows positioning of the arm and hand in space. Compared to those patients left without a scapula reconstruction, prosthetic replacement of the scapula and shoulder partially restores abduction and external rotation and improves cosmesis.

Limb salvage surgery using the intramedullary diaphyseal segmental defect fixation system.

Six patients underwent segmental bone resection and limb salvage surgery for primary or metastatic bone tumors involving the diaphysis of the femur, the tibia, and the humerus using a modular intramedullary diaphyseal segmental defect fixation system. There were four men and two women with a mean age of 62 years (range: 40-77 years). Histological diagnosis included adamantinoma, synovial sarcoma, multiple myeloma, metastatic renal cell carcinoma, myeloid carcinoma of the thyroid gland, and adenocarcinoma of the stomach. The mean follow-up was 17 months (range: 11-28 months). At the latest examination, five patients were free of local or distant disease and one patient had deceased with distant disease, without evidence of local recurrence. Revision surgery was necessary in one patient because of mechanical loosening of the proximal fixation of the prosthesis at 24 months. The mean postoperative increase of the Enneking rating score was 87.8%. The intramedullary diaphyseal segmental defect fixation system used herein is associated with a satisfactory functional and oncological outcome after wide resection of diaphyseal bone tumors.

Three-dimensional Technologies in Orthopedics.

New 3-dimensional digital technologies are revolutionizing orthopedic clinical practice, allowing structures of any complexity to be manufactured in just hours. Such technologies can make surgery for complex cases more precise, more cost-effective, and possibly easier to perform. Applications include pre-operative planning, surgical simulation, patient-specific instrumentation and implants, bioprinting, prosthetics, and orthotics. The basic principles of 3- dimensional technologies, including imaging, design, numerical simulation, and printing, and their current applications in orthopedics are reviewed. [Orthopedics. 2018; 41(1):12-20.].

Periprosthetic Fractures in Megaprostheses: Algorithmic Approach to Treatment.

With increases in both life expectancy and the number of patients with endoprosthetic replacements, more periprosthetic fractures are expected to occur. Periprosthetic fractures related to megaprostheses present a treatment challenge, with a high incidence (one-third of affected patients) of secondary revision as a result of prosthetic loosening, infection, nonunion, refracture, or even amputation. Efforts to improve endoprosthetic reconstruction should focus on preventing postoperative complications. Understanding the causes of complications and strategies to avoid them could lead to significant improvements in implant survival, limb function, and patient outcomes. This article presents a concise review of the current literature and an algorithmic approach to reconstruction of these complex injuries. [Orthopedics. 2017; 40(3):e387-e394.].

Risk Assessment for Chronic Pain and Patient Satisfaction After Total Knee Arthroplasty.

The estimated prevalence of patients who report minor or no improvement of their symptoms and pain after total knee arthroplasty (TKA) remains high, ranging from 5% to 40%. The authors sought to determine whether chronic pain and functional health are related to specific variations in demographic data, surgical techniques, or radiographic pre- and postoperative findings. They also sought to identify independent risk factors for persistent moderate-to-severe chronic pain after TKA. A total of 273 patients who underwent primary TKA from October 2007 to March 2010 with a minimum follow-up of 1 year were identified from electronic medical records. A questionnaire to identify persistent postoperative pain (36-item Short Form Health Survey [SF-36]) was mailed to these patients. Linear regression and logistic regression were used to identify predictors for SF-36 and chronic pain, respectively. Thirty-nine percent of patients reported persistent pain after TKA, with a median average pain score of 3 out of 10 and worst pain score of 5 out of 10. Independent risk factors for persistent pain are the length of the operative procedure (odds ratio [OR]=1.013), medical history of diabetes mellitus (OR=0.430), presence of preoperative flexion contracture (OR=1.089), and patellofemoral joint overstuffing (OR=0.915). Persistent postoperative pain is a common finding after TKA. Nonmodifiable risk factors could be used for risk stratification, whereas modifiable risk factors could be used as a clinical guidance for modification of some aspects of existing surgical techniques.

Clinical Spectrum and Management of Caustic Ingestion: A Case Series Presenting Three Opposing Outcomes.

BACKGROUND: Ingestion of caustic substances is a medical emergency in both the adult and pediatric population and is associated with high morbidity and mortality. The extent of injuries after ingestion of caustic substances depends on the nature, amount, and concentration of the agent and on the exposure time. Acutely, caustic substances may cause massive hemorrhage and gastrointestinal tract perforation; the most markedly affected cases require urgent surgical treatment. Patients surviving the initial event may present with aorto-enteric or gastrocolic fistulae, esophageal strictures, dysphagia, and increased risk of esophageal cancer as long term sequelae. CASE REPORT: The features of three cases of caustic ingestion are reported to demonstrate significantly different complaints presented at the emergency department. Two patients had free gastric perforation, one at presentation, and one delayed. The third patient presented with late severe strictures of the esophagus and pylorus. The outcomes of the three patients are discussed in detail along with the most current management strategies. CONCLUSIONS: Among adults, ingestion of caustic substances is usually associated with more severe lesions due to the increased amount of ingested substance, as compared with pediatric patients. The most serious presentation is that of visceral perforation, most commonly of the stomach and rarely of the esophagus. Management involves urgent resuscitation with correction of fluid and electrolyte and acid-base abnormalities and immediate surgical exploration in those patients with signs of perforation. Once the perioperative period is managed successfully, the long-term results can be satisfactory. Managing of strictures or else reconstructive procedures must be well timed to allow for psychological and nutritional rehabilitation.

Applied Nanotechnology and Nanoscience in Orthopedic Oncology.

Nanomedicine is based on the fact that biological molecules behave similarly to nanomolecules, which have a size of less than 100 nm, and is now affecting most areas of orthopedics. In orthopedic oncology, most of the in vitro and in vivo studies have used osteosarcoma or Ewing sarcoma cell lineages. In this article, tumor imaging and treatment nanotechnology applications, including nanostructure delivery of chemotherapeutic agents, gene therapy, and the role of nano-selenium-coated implants, are outlined. Finally, the potential role of nanotechnology in addressing the challenges of drug and radiotherapy resistance is discussed. [Orthopedics. 2016; 39(5):280-286.].