Adam Sassoon

Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

BackgroundPatient-specific cutting blocks have been touted as a more efficient and reliable means of achieving neutral mechanical alignment during TKA with the proposed downstream effect of improved clinical outcomes. However, it is not clear to what degree published studies support these assumptions.Questions/purposesWe asked: (1) Do patient-specific cutting blocks achieve neutral mechanical alignment more reliably during TKA when compared with conventional methods? (2) Does patient-specific instrumentation (PSI) provide financial benefit through improved surgical efficiency? (3) Does the use of patient-specific cutting blocks translate to improved clinical results after TKA when compared with conventional instrumentation?MethodsWe performed a systematic review in accordance with Cochrane guidelines of controlled studies (prospective and retrospective) in MEDLINE® and EMBASE® with respect to patient-specific cutting blocks and their effect on alignment, cost, operative time, clinical outcome scores, complications, and survivorship. Sixteen studies (Level I–III on the levels of evidence rubric) were identified and used in addressing the first question, 13 (Level I–III) for the second question, and two (Level III) for the third question. Qualitative assessment of the selected Level I studies was performed using the modified Jadad score; Level II and III studies were rated based on the Newcastle-Ottawa scoring system.ResultsThe majority of studies did not show an improvement in overall limb alignment when PSI was compared with standard instrumentation. Mixed results were seen across studies with regard to the prevalence of alignment outliers when PSI was compared with conventional cutting blocks with some studies demonstrating no difference, some showing an improvement with PSI, and a single study showing worse results with PSI. The studies demonstrated mixed results regarding the influence of PSI on operative times. Decreased operative times were not uniformly observed, and when noted, they were found to be of minimal clinical or financial significance. PSI did reliably reduce the number of instrument trays required for processing perioperatively. The accuracy of the preoperative plan, generated by the PSI manufacturers, was found lacking, often leading to multiple intraoperative changes, thereby disrupting the flow of the operation and negatively impacting efficiency. Limited data exist with regard to the effect of PSI on postoperative function, improvement in pain, and patient satisfaction. Neither of the two studies we identified provided strong evidence to support an advantage favoring the use of PSI. No identified studies addressed survivorship of components placed with PSI compared with those placed with standard instrumentation.ConclusionsPSI for TKA has not reliably demonstrated improvement of postoperative limb or component alignment when compared with standard instrumentation. Although decisive evidence exists to support that PSI requires fewer surgical trays, PSI has not clearly been shown to improve overall surgical efficiency or the cost-effectiveness of TKA. Mid- and long-term data regarding PSI’s effect on functional outcomes and component survivorship do not exist and short-term data are scarce. Limited available literature does not clearly support any improvement of postoperative pain, activity, function, or ROM when PSI is compared with traditional instrumentation.

Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis

Osteoarthritis (OA) ranks globally among the 50 most common sequelae of diseases and injuries, affecting over 250 million people or 4% of the world’s population [39]. Of the global disease burden for OA, knee OA constitutes 83% [39]. A detailed analysis of Medicare beneficiaries reported the TKA annual utilization rate ranging from 287,006 in 2006 to 301,956 in 2010 [26]. The demand for TKA is expected to grow exponentially over the coming decades with epidemiological data suggesting a 673% increase in the United States by 2030, representing 3.48 million procedures annually [22]. As a polymorphic disease with a variety of clinical presentations, OA is challenging to rigorously define. A commonly encountered definition of OA describes ‘‘...a heterogeneous group of conditions that leads to joint symptoms and signs which are associated with defective integrity of articular cartilage, in addition to related changes in the underlying bone and at the joint margins’’ [1]. The pathogenesis of OA is poorly understood but is thought to include a complex interplay among mechanical, biochemical, cellular, genetic, and immunologic phenomena [7]. Several attempts to develop diagnostic criteria for OA were previously undertaken and incorporate patientreported joint pain in conjunction with consistent radiographic findings [1, 6, 24]. OA generally can be subcategorized into primary (idiopathic) and secondary OA [1, 25]. Common causes of secondary OA include posttraumatic, dysplastic, infectious, inflammatory, or biochemical etiologies that are relatively well understood. Although the etiology of primary OA remains largely undefined, genetic factors, age-related physiological changes, ethnicity, and biomechanical factors likely play an important role [16]. Plain radiography remains a mainstay in the diagnosis of OA. The first formalized attempts at establishing a radiographic classification scheme for OA were described by Kellgren and Lawrence (KL) in 1957 [19]. After studying rheumatism in coal miners at the Bedford Colliery in North West England [18], Kellgren investigated the interand intraobserver reliability of radiographic changes of rheumatism observed in the hand [17]. After concluding that there was wide disagreement among different observers, KL endeavored to establish a classification scheme with an associated set of standardized radiographs for OA of diarthrodial joints. They proposed a five-grade classification scheme and examined plain radiographs of eight joints including the distal interphalangeal joint (DIP), metacarpophalangeal joint (MCP), first carpometacarpal joint (CMC), wrist, cervical spine, lumbar spine, hips, and knees to calculate the interand intraobserver reliability of each [19]. They found that the tibiofemoral joint of the knee had the highest interobserver correlation coefficient of r = 0.83 (range of all joints studied, 0.10–0.83) as well as the second highest intraobserver correlation coefficient of Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request.

Contemporary Surgical Indications and Referral Trends in Revision Total Hip Arthroplasty: A 10-Year Review

BACKGROUND Revision total hip arthroplasty (THA) represents nearly 15% of all hip arthroplasty procedures in the United States and is projected to increase. The purpose of our study was to summarize the contemporary indications for revision THA surgery at a tertiary referral medical center. We also sought to identify the indications for early and late revision surgery and define the prevalence of outside institution referral for revision THA. METHODS Using our institutions arthroplasty registry, we identified a retrospective cohort of 870 consecutive patients who underwent revision THA at our hospital from 2004 to 2014. Records were reviewed to collect data on patients primary and revision THA procedures, and the interval between primary THA and revision surgery was determined. RESULTS Aseptic loosening (31.3%), osteolysis (21.8%), and instability (21.4%) were the overall most common indications for revision THA and the most common indications for revision surgery within 5 years of primary THA. Aseptic loosening and osteolysis were the most common indications for revision greater than 5 years from primary THA. Only 16.4% of revised hips had their index arthroplasty performed at our hospital, whereas 83.6% were referred to our institution. CONCLUSIONS Aseptic loosening, osteolysis, and instability remain the most common contemporary indications for revision THA in an era of alternative bearings and modular components. Most of our revisions were referred from outside institutions, which highlights the transfer of a large portion of the revision THA burden to tertiary referral centers, a pattern that could be exacerbated under future bundled payment models.

Pseudotumour formation and subsequent resolution in metal-on-metal total hip arthroplasty following revision: Instructional review and an illustrative case report with revision using a dual mobility design

The use of large-diameter metal-on-metal (MoM) components in total hip arthroplasty (THA) is associated with an increased risk of early failure due to adverse local tissue reaction to metal debris (ARMD) in response to the release of metal ions from the bearing couple and/or head-neck taper corrosion. The aim of this paper was to present a review of the incidence and natural history of ARMD and the forms of treatment, with a focus on the need for and extent of resection or debulking of the pseudotumour. An illustrative case report is presented of a patient with an intra-pelvic pseudotumour associated with a large diameter MoM THA, which was treated successfully with revision of the bearing surface to a dual mobility couple and retention of the well-fixed acetabular and femoral components. The pseudotumour was left in situ Resolution of the intra-pelvic mass and normalisation of metal ion levels was observed seven months post-operatively. Cite this article: Bone Joint J 2016;98-B:736-40.

Younger patients have less severe radiographic disease and lower reported outcome scores than older patients undergoing total knee arthroplasty.

BACKGROUND Total knee arthroplasty (TKA) has been successful for many younger patients, but some experience residual symptoms or dissatisfaction. We performed this study to assess the relationship between radiographic disease severity and patient demographic features on patient reported TKA outcome scores. METHODS We compared 100 TKAs performed for 82 patients ≤55years old with 100 gender-matched TKAs performed for 85 patients between 65 and 75years old. These study cases represented 25% and 21%, respectively, of TKAs performed between January 2006 and June 2011. Radiographic disease severity was determined from preoperative weight bearing AP and lateral radiographs. Patient reported outcome instruments (SF-12, Knee Society function, and WOMAC) were assessed for all patients within six months before surgery and postoperatively at a mean of 20months after TKA. RESULTS Although younger patients had less mean articular cartilage loss (p<0.01), osteoarthritis severity (p<0.01), and Kellgren-Lawrence grade (p=0.05), they reported lower preoperative scores (p<0.01) exceeding the MCID for SF-12 mental health (8.3 points), WOMAC pain (12.1 points), and WOMAC physical function (6.9 points). While substantial improvement was noted, WOMAC pain scores remained lower than those reported by older TKA patients (11.5 points, p<0.05). CONCLUSION Younger patients with less severe radiographic arthritis experience significant improvement with TKA, but outcome scores do not match those attained by older patients with more severe radiographic disease.

Intraoperative Fracture During Aseptic Revision Total Knee Arthroplasty

Bone encountered during revision knee arthroplasty is compromised and predisposed to fracture. This study reports the rate, location, timing, treatment, and outcome of intraoperative fractures occurring during revision knee arthroplasty. Between 1997 and 2011, 2836 aseptic revisions were performed. Ninety-seven fractures were identified in 89 patients (3%). Fifty occurred in femora, 42 in tibiae, and 5 in patellae. Forty-six occurred during exposure, 21 during bony preparation, 17 during trialing, and 13 during final component placement. Treatment included fixation (n = 43), observation (n = 21), component build-up (n = 17), bone grafting (n = 6), and a combination (n = 3). Ninety-four percent of fractures united. Fifteen patients required a re-revision (17%), of which infection was the leading cause (n = 5).

Periprosthetic patellar fractures.

Periprosthetic patellar fractures represent a spectrum of injuries to a patient with a total knee arthroplasty. They range in severity from an inconsequential injury, which does not compromise function, to a severely debilitating injury that may require advanced reconstructive measures. This article will outline the epidemiology and risk factors associated with periprosthetic patellar fractures. Treatment options as they relate to injury mechanism, fracture severity, patellar component stability, and remaining bone stock will also be discussed. Finally, a review of the current literature regarding the results of treatment will be presented.

Classifications In Brief: The Tscherne Classification of Soft Tissue Injury

Soft tissue injuries are an intrinsic component of any fracture. Treatment of these soft tissue injuries is challenging, but is an integral element of fracture care. The initial evaluation of a patient with orthopaedic trauma must include a detailed assessment of the soft tissue envelope. The timing and method of fracture fixation are directly influenced by the degree of trauma to the overlying soft tissues and have been shown to have a direct effect on postoperative function [5, 8, 13, 14, 17]. Various classification systems have been proposed to help communicate, classify, and guide treatment of soft tissue injuries occurring in the setting of fractures. These include the Tscherne classification for open and closed fractures [36], Gustilo and Anderson classification for open fractures [15, 16], Hannover fracture scale [35], and the AO soft tissue grading system [31]. Developed by Harald Tscherne and Hans-Jörg Oestern in 1982 at the Hannover Medical School (Hanover, Germany), the Tscherne classification for closed and open fractures [36] has become a frequently referenced system for defining soft tissue injuries. They based their classification on the apparent kinetic energy imparted on soft tissue in fracture trauma and the physiologic consequence of this trauma on the overlying soft tissue envelope.

Tranexamic acid: optimal blood loss management in surface replacement arthroplasty

AIMS This study investigated whether the use of tranexamic acid (TXA) decreased blood loss and transfusion related cost following surface replacement arthroplasty (SRA). METHODS A retrospective review of patients treated with TXA during a SRA, who did not receive autologous blood (TXA group) was performed. Two comparison groups were established; the first group comprised of patients who donated their own blood pre-operatively (auto group) and the second of patients who did not donate blood pre-operatively (control). Outcomes included transfusions, post-operative haemoglobin (Hgb), complications, and length of post-operative stay. RESULTS Between 2009 and 2013, 150 patients undergoing SRA were identified for inclusion: 51 in the auto, 49 in the control, and 50 in the TXA group. There were no differences in the pre-operative Hgb concentrations between groups. The mean post-operative Hgb was 11.3 g/dL (9.1 to 13.6) in the auto and TXA groups, and 10.6 g/dL (8.1 to 12.1)in the control group (p = 0.001). Accounting for cost of transfusions, administration of TXA, and length of stay, the cost per patient was

What Editors and Reviewers Look for: Tips for Successful Research Publication

1731,