Surgeon Undertaking Research Articles

Mechanisms of bone loss in revision total knee arthroplasty and current treatment options.

Primary total knee arthroplasty (TKA) is an effective treatment which is increasing in use for both elderly and younger patients. With the overall increasing life span of the general population, the rate of revision TKA is projected to increase significantly over the coming decades. Analyses from the national joint registry of England and Wales support this prediction with an increase in primary TKA of 117% and an increase in revision TKA of 332% being forecast by 2030. Bone loss presents a challenge in revision TKA so an understanding of the aetiology and principles behind this is essential for the surgeon undertaking revision. The purpose of this article is to review the causes of bone loss in revision TKA, discuss the mechanisms of each cause and discuss the possible treatment options. The Anderson Orthopaedic Research Institute (AORI) classification and zonal classification of bone loss are commonly used in assessing bone loss in pre-operative planning and will be used in this review. The recent literature was searched to find advantages and limitations of each commonly used method to address bone loss at revision TKA. Studies with the highest number or patients and longest follow-up period were selected as significant. Search terms were: "aetiology of bone loss", "revision total knee arthroplasty", "management of bone loss". Methods for managing bone loss have traditionally been cement augmentation, impaction bone grafting, bulk structural bone graft and stemmed implants with metal augments. No single technique was found to be superior. Megaprostheses have a role as a salvage procedure when the bone loss is deemed to be too significant for reconstruction. Metaphyseal cones and sleeves are a newer treatments with promising medium to long term outcomes. Bone loss encountered at revision TKA presents a significant challenge. No single technique currently has clear superiority treatment should be based on a sound understanding of the underlying principles.

Extra-articular tibial deformity management in total knee replacement.

Presence of an extra-articular deformity in the femur or tibia poses a challenge to the surgeon undertaking knee replacement procedure. The conundrum is whether to correct the deformity beforehand, or accept the deformity and compensate for this through placement of the implant. This is a retro-spective study comprising six patients who had a knee replacement in the presence of an extra-articular deformity of the tibia treated at our centre. All six had the knee replacement without correction of deformity. The data evaluated included clinical outcome, mechanical axis correction, type of implant, and the use of any software / computer guidance. Mean age was 66.5 years. Mean coronal plane deformity in the tibia was 8.6 degrees. The hip- knee-ankle improved from a mean 12.6 degrees to 4 degrees. Mean Oxford knee score improved from a mean of 19 to 33.6. Planning the tibial resection on the basis of mechanical axis of tibia allows correction of alignment without the need for preoperative correction.

Irrigation and Debridement with Chronic Antibiotic Suppression Is as Effective as 2-Stage Exchange in Revision Total Knee Arthroplasty with Extensive Instrumentation

Extraction of implants because of periprosthetic infection (PJI) following complex revision total knee arthroplasty (rTKA) with extensive instrumentation is a daunting undertaking for surgeon and patient alike. The purpose of the present study was to evaluate whether infections following complex rTKA are better treated with 2-stage exchange or irrigation and debridement (I&D) with modular component exchange and antibiotic suppression in terms of infection control, reoperation, and function. We reviewed rTKAs that had been performed for the treatment of PJI from 2005 to 2016. Extensive instrumentation was defined as the presence ≥1 of the following: metaphyseal cones/sleeves, distal femoral replacement, periprosthetic fracture instrumentation, or fully cemented stems measuring >75 mm. Cases were categorized according to the initial treatment (I&D with antibiotic suppression or initiation of 2-stage exchange). Eighty-seven patients with PJI and extensive instrumentation were identified: 56 patients who were managed with I&D with suppression and 31 who were managed with the initiation of 2-stage exchange. The rate of success (defined as no reoperation for infection) was similar for the 2 groups (62.5% the I&D group compared with 67.7% for the 2-stage group; p = 0.62). The rate of mortality was also similar (39.3% for the I&D group compared with 38.7% for the 2-stage group; p = 0.96). Of the 31 patients in the 2-stage group, 18 (58.1%) underwent reimplantation with a revision replacement. Of those 18 patients, 13 were still infection-free at the time of the most recent follow-up; however, when the analysis was expanded to all 31 patients in the 2-stage group, only 13 (41.9%) both had a successful reimplantation and did not require additional surgery for infection. Nine (29.0%) of the 31 patients in the 2-stage group never underwent the second stage, and 4 (12.9%) of the 31 required arthrodesis at the second stage. In contrast, 35 (62.5%) of the 56 patients in the I&D group were successfully managed, without additional surgery for the treatment of infection. At the time of the latest follow-up (mean, 3.2 years; range, 2 to 13 years), more patients in the I&D group were ambulatory (76.8% in the I&D group compared with 54.8% in the 2-stage group; p = 0.05) and maintained a functional bending knee joint (85.7% in the I&D group compared with 45.2% in the 2-stage group; p < 0.001). In the treatment of periprosthetic infection of rTKA with extensive instrumentation, I&D with chronic antibiotic suppression was as effective as 2-stage exchange in terms of preventing reoperation for infection and was more effective in terms of maintaining function. These data apply to rTKA with extensive periarticular instrumentation and should not be extrapolated to primary or simple revision implants. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Parastomal hernia - current knowledge and treatment.

Intestinal stoma creation is one of the most common surgical procedures. The most common long-term complication following stoma creation is parastomal hernia, which according to some authors is practically unavoidable. Statistical differences of its occurrence are mainly due to patient observation time and evaluation criteria. Consequently, primary prevention methods such as placement of prosthetic mesh and newly developed minimally invasive methods of stoma creation are used. It seems that in the light of evidence-based medicine, the best way to treat parastomal hernia is the one that the surgeon undertaking therapy is the most experienced in and is suited to the individuality of each patient, his condition and comorbidities. As a general rule, reinforcing the abdominal wall with a prosthetic mesh is the treatment of choice, with a low rate of complications and relapses over a long period of time. The current trend is to use lightweight, large pore meshes.

High-Volume Hospitals with High-Volume and Low-Volume Surgeons: Is There a “Field Effect” for Pancreaticoduodenectomy?

Since the Leapfrog Group established hospital volume criteria for pancreaticoduodenectomy (PD), the importance of surgeon volume versus hospital volume in obtaining superior outcomes has been debated. This study was undertaken to determine whether low-volume surgeons attain the same outcomes after PD as high-volume surgeons at high-volume hospitals. PDs undertaken from 2010 to 2012 were obtained from the Florida Agency for Health Care Administration. High-volume hospitals were identified. Surgeon volumes within were determined; postoperative length of stay (LOS), in-hospital mortality, discharge status, and hospital charges were examined relative to surgeon volume. Six high-volume hospitals were identified. Each hospital had at least one surgeon undertaking ≥ 12 PDs per year and at least one surgeon undertaking < 12 PDs per year. Within these six hospitals, there were 10 "high-volume" surgeons undertaking 714 PDs over the three-year period (average of 24 PDs per surgeon per year), and 33 "low-volume" surgeons undertaking 225 PDs over the three-year period (average of two PDs per surgeon per year). For all surgeons, the frequency with which surgeons undertook PD did not predict LOS, in-hospital mortality, discharge status, or hospital charges. At the six high-volume hospitals examined from 2010 to 2012, low-volume surgeons undertaking PD did not have different patient outcomes from their high-volume counterparts with respect to patient LOS, in-hospital mortality, patient discharge status, or hospital charges. Although the discussion of volume for complex operations has shifted toward surgeon volume, hospital volume must remain part of the discussion as there seems to be a hospital "field effect."

The Post-Levator Aponeurosis Fat Pad.

To examine the post-aponeurotic space and to confirm and define the presence of a post-aponeurosis fat-pad. Experimental anatomic study. Nineteen-orbits from 10 freeze-preserved, unembalmed cadavers of caucasian subjects. In 12 orbits of 7 cadavers, a transconjunctival dissection of the everted upper eyelid was undertaken. Müller's muscle (MM) and conjunctiva were dissected as a composite flap exposing the posterior surface of the aponeurosis (LA) and the commencement of the levator palpebrae superioris (LPS) muscle. Anatomical localisation was agreed by 2 senior surgeons and an anatomist (VM). In the remaining 7 orbits a 1cm central upper eyelid wedge-excision was paraffin-embedded and studied histologically. Nineteen upper-eyelids from 10 freeze-preserved, unembalmed caucasian cadavers (5-male, 5-female, mean age 80.9; range 67-91 years) were studied. Of 12 eyelids of 7 cadavers, dissected and macroscopically evaluated, a fat-pad was identified in the post-aponeurotic space of all eyelids. Of these, 8 (66%) were predominantly diffuse. The remainder, mixed diffuse-discrete. All 4 of the latter category appeared multi-lobular. The fat-pad was seen to lie predominantly centro-medially, overlying MM, extending superiorly beyond the LA to lie posterior to LPS. Of the 7 upper eyelid wedge-excisions examined microscopically, a fat-pad was identified in all post-aponeurotic spaces, lying between 2 distinct tracts of smooth muscle. The anterior smooth muscle tract was intimately related to the posterior aspect of the LA, in keeping with the posterior smooth muscle layer of the aponeurosis. The posterior smooth muscle tract was in keeping with MM, thicker than the anterior layer, multi-layered and in 6 of 7 eyelids, interspersed with fat. We confirm and describe a distinct layer of fat in the post-aponeurotic space, consistently found between MM and the posterior smooth muscle layer of the aponeurosis. We refer to this as the post-aponeurosis fat-pad. These findings provide further anatomical detail for the surgeon undertaking blepharoptosis surgery, who may, in some cases, mistake the presence of fat in this space either for the pre-aponeurotic fat-pad, or for degenerative changes within MM that lies deep to it.

Intervention on thoracic and thoracoabdominal aortic aneurysms: can the UK offer a service?

Descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms are classified according to their longitudinal extent, at their greatest reaching from left subclavian artery to iliac vessels and involving two body cavities.1 The natural history of thoracoabdominal aortic aneurysms is difficult to determine accurately; however, several studies have estimated survival in patients followed up after having been turned down for surgery or declining intervention.1,2 The outlook for these patients is poor. In Crawfords original series (1986)1 of 94 unoperated patients, the two-year survival was 24%. A larger study by Perko et al. (1995)2 documented similarly poor outcomes with five-year survival of 0.39 ± 0.07, 0.23 ± 0.06 and 0.18 ± 0.05 for isolated thoracic aneurysms, thoracoabdominal aneurysms and abdominal aortic aneurysms, respectively. This has not improved despite current optimal medical therapy; however, predicting annual risk of rupture has become accurate allowing timely intervention in an elective setting.3,4 Risk of rupture is most strongly related to diameter with the so-called ‘hinge point’ being around 7 cm in the descending thoracic aorta, at which point 43% of those under follow-up will have ruptured or dissected.5 In asymptomatic patients the indication for surgery occurs roughly when the annual risk of rupture is greater than the perioperative risk of death.4 Intervention is a major undertaking for surgeon and patient. Open surgery has improved significantly over recent years; however, even in high-volume reference centre risks remain substantial for the largest of aneurysms (death [10%], paraplegia [7.5%] and renal failure [15.9%]6). However, data from this same group6 suggest much improved survival following surgery, with five-year survivals between 66% and 75%, depending on the severity of the aneurym, significantly better than that estimated in natural history studies. Relatively recently, endovascular approaches have been pioneered to circumvent the need for extensive high-risk surgery; however, these approaches have not been without their problems, including high cost and re-intervention rates.7 Hybrid approaches with endovascular stenting and re-routing of visceral vessels have been published by several groups, including some in the UK,8 but seem to offer no clear advantage. The literature remains controversial and no randomized trial has been performed comparing best medical therapy with surgery, stent or a hybrid procedure. American Heart Association guidelines9 and international consensus statements7 exist and provide a comprehensive comparison of these various approaches and we do not intend to reproduce the arguments here. The picture in the UK remains particularly unclear with respect to prevalence, intervention, outcome and arrangement of services. This essay attempts to estimate the consumption of medical services by patients with this condition within the UK, attempts to understand the intervention rate and form and asks whether the UK can offer a service with adequate outcomes at acceptable costs.

The Rationale for Direct Linear Closure of Facial Mohsʼ Defects

Closing Mohs' defects is a challenging undertaking for surgeons. There are many methods, including linear repair, local flaps, and skin grafts. Traditionally, geometric flaps have been a mainstay, particularly in the cheek and forehead. However, many flaps violate basic principles of following relaxed skin tension lines; also, they often necessitate significant dissection. All repairs of Mohs' facial defects performed sequentially from 2001 to 2008 by the senior author (J.F.T.) were reviewed. Chart review identified the size and location of the defect, method of closure, and complications. Chart review revealed 1354 reconstructions, with 475 direct repairs (35 percent). The highest rate of direct repair was seen in the forehead (77 percent). The lowest rate of direct repair was seen in the nose (7 percent). Analysis of cases revealed good results, with very low morbidity for direct linear closure. For many large defects, the simple method of direct linear closure often yields results superior to those of more time-consuming local flap options. Several dogmas of facial reconstruction are too unyielding, and the option of direct repair should not be overlooked. Traditional estimates of defect size requiring flap repair are incorrect; it is possible to close some large defects by direct approximation, with superior results.

Psychosocial and marketing challenges for Natural Orifice Transluminal Endoscopic Surgery and Laparoendoscopic Single‐site Surgery

The introduction of laparoscopic techniques in the late 1980s and early 1990s has ushered in a novel era in the surgical treatment of human diseases. Following the first laparoscopic nephrectomy done by Clayman et al . in 1991 [1], the initially noted advantages of minimally invasive urological surgery were later proved [2,3]. This soon led to the transition from novelty to the current concept of established ‘expectations’. Despite the success of conventional laparoscopic urological surgery, incisions ranging from 1 to 3 cm in length and three to five ports in number are still required. Each additional working port increases the inherent risk of bleeding, infection, concordant organ damage, hernia formation and decreased cosmetic outcome.

The effect of posterior bridging of C-1 on craniovertebral junction surgery

The groove for the vertebral artery (VA) may be bridged on C-1, forming a canal through which the artery passes. Because this variant may significantly affect the commonly performed C-1 posterior laminectomy, the authors studied the incidence and radiological appearance of this anatomical feature in surgical specimens. Anatomical measurements were performed using a Vernier caliper (accurate to 0.1 mm) on 166 dry C-1 vertebrae. In addition, a convenience sample of 172 cervical x-ray films was evaluated. Partial osseous bridging was detected in eight (4.8%), and a complete osseous bridge, forming the canalis arteriae vertebralis (canal for the VA), was seen unilaterally (eight on the left and two on the right) in 10 (6%) and bilaterally in eight (4.8%) of the dry vertebrae. On lateral radiography, a complete bone bridge was observed on nine (5.2%) and a partial bridge on 10 (5.8%) of the 172 studies. The discovery of a common variant may necessitate an immediate change in surgical management, and this anomaly could even increase the rate of surgery-related complications. The VA canal, present in the C-1 vertebra in approximately 5% of the specimens evaluated, was a variant that may be protective against VA injury. Knowledge of this variant may help the surgeon undertaking procedures in the C-1 region.

A technique for frameless stereotaxy and placement of transarticular screws for atlanto-axial instability in rheumatoid arthritis

The aim of the present study was to outline a new surgical technique and describe how, in a clinical setting, computer-generated image-guidance can assist in the planning and accurate placement of transarticular C1/C2 screws inserted using a minimally invasive exposure. Forty-six patients with atlanto-axial instability due to rheumatoid arthritis underwent posterior stabilisation with transarticular screws. This was achieved with a minimal posterior exposure limited to C1 and C2 and percutaneous screw insertions via minor stab incisions. The Stealth Station (Medtronic Sofamor Danek, Memphis, Tenn., USA) was used for image guidance to navigate safely through C2. Reconstructed computed tomographic (CT) scans of the atlanto-axial complex were used for image guidance. It was possible to perform preoperative planning of the screw trajectory taking into account the position of the intraosseous portion of the vertebral arteries, the size of the pars interarticularis and the quality of bone in C2. Screws could be inserted percutaneously over K-wires using a drill guide linked to the image-guidance system. Preoperative planning was performed in all 46 patients and accurate registration allowed proposed screw trajectories to be identified. Thirty-eight patients had bilateral screws inserted and eight had a unilateral screw. A total of 84 screws were inserted using the Stealth Station. There were no neurovascular injuries. This technique for placing transarticular screws is accurate and safe. It allows a minimally invasive approach to be followed. Image guidance is a useful adjunct for the surgeon undertaking complex spinal procedures.

Femoral stem disengagement in modular total knee revision arthroplasty

Modularity of tibial and femoral components allows the surgeon undertaking revision total knee arthroplasty a wide variety of options when trying to restore the joint line and balance the soft tissues in the presence of bone loss secondary to osteolysis. The results of small series reported in the literature demonstrate encouraging results at short-term follow-up. Concerns over galvanic corrosion and fretting between augments, intramedullary stems and prostheses have not been realized clinically. Complications of the procedure include those common to all surgical procedures as well as chronic pain about the knee and prosthetic loosening. We report a case of very early disengagement of a femoral intramedullary stem and its clinical and radiological effects at 3 years.

Abdominal aortic surgery and the left renal vein

The existence of variations in the anatomy of the left renal vein is an important consideration for the surgeon undertaking resection or reconstruction of the abdominal aorta. These variations are not uncommon and an awareness of them is essential in preventing troublesome operative complications. Sacrifice of the left renal vein may occasionally be necessary, and if care is taken to ligate the vein on the vena caval side of the adrenal and spermatic veins and to preserve these veins, serious damage to the kidney is unlikely although not impossible.