Pramod B. Voleti

Tendon healing: Repair and regeneration

Injury and degeneration of tendon, the soft tissue that mechanically links muscle and bone, can cause substantial pain and loss of function. This review discusses the composition and function of healthy tendon and describes the structural, biological, and mechanical changes initiated during the process of tendon healing. Biochemical pathways activated during repair, experimental injury models, and parallels between tendon healing and tendon development are emphasized, and cutting-edge strategies for the enhancement of tendon healing are discussed.

Current Data Do Not Support Routine Use of Patient-Specific Instrumentation in Total Knee Arthroplasty

The purpose of this systematic review and meta-analysis is to compare patient-specific instrumentation (PSI) versus standard instrumentation for total knee arthroplasty (TKA) with regard to coronal and sagittal alignment, operative time, intraoperative blood loss, and cost. A systematic query in search of relevant studies was performed, and the data published in these studies were extracted and aggregated. In regard to coronal alignment, PSI demonstrated improved accuracy in femorotibial angle (FTA) (P=0.0003), while standard instrumentation demonstrated improved accuracy in hip-knee-ankle angle (HKA) (P=0.02). Importantly, there were no differences between treatment groups in the percentages of FTA or HKA outliers (>3 degrees from target alignment) (P=0.7). Sagittal alignment, operative time, intraoperative blood loss, and cost were also similar between groups (P>0.1 for all comparisons).

Use of static or articulating spacers for infection following total knee arthroplasty: a systematic literature review.

BACKGROUND The so-called gold standard for treatment of periprosthetic joint infection following total knee arthroplasty is two-stage reimplantation. However, it is unclear whether use of static or articulating antibiotic-impregnated spacers during the interim period between these two stages is superior. The purpose of this study was to compare the outcomes of static and articulating spacers in the treatment of infection following total knee arthroplasty. METHODS A systematic review of the peer-reviewed literature indexed by MEDLINE and Embase was performed to identify studies reporting the outcomes of antibiotic spacers in the treatment of infection following total knee arthroplasty. Seven Level-III comparative studies and thirty-two Level-IV case series remained following the screening process. The data in these studies were extracted and aggregated to compare the reinfection rate, range of knee motion, functional scores, and complication rates between static and articulating spacers. RESULTS The two types of spacers demonstrated similar reinfection rates (7% for articulating and 12% for static, p = 0.2). However, the articulating spacers resulted in significantly greater range of knee motion after reimplantation (101° for articulating and 91° for static, p = 0.0002). Despite this difference in ultimate knee motion, functional scores in the treatment groups were similar. Rates of wound-related and spacer-related complications were similarly low with both types of spacers. CONCLUSIONS Our review failed to identify a significant difference in the ability of static or articulating spacers to eradicate periprosthetic infection following total knee arthroplasty. Compared with static spacers, articulating spacers provided improved knee motion following reimplantation, although functional scores were similar in the two treatment groups. We encourage arthroplasty surgeons to consider both static and articulating spacers in the treatment of infection following total knee arthroplasty and to tailor treatment on the basis of patient-related factors.

Biomechanical and structural response of healing Achilles tendon to fatigue loading following acute injury

Achilles tendon injuries affect both athletes and the general population, and their incidence is rising. In particular, the Achilles tendon is subject to dynamic loading at or near failure loads during activity, and fatigue induced damage is likely a contributing factor to ultimate tendon failure. Unfortunately, little is known about how injured Achilles tendons respond mechanically and structurally to fatigue loading during healing. Knowledge of these properties remains critical to best evaluate tendon damage induction and the ability of the tendon to maintain mechanical properties with repeated loading. Thus, this study investigated the mechanical and structural changes in healing mouse Achilles tendons during fatigue loading. Twenty four mice received bilateral full thickness, partial width excisional injuries to their Achilles tendons (IACUC approved) and twelve tendons from six uninjured mice were used as controls. Tendons were fatigue loaded to assess mechanical and structural properties simultaneously after 0, 1, 3, and 6 weeks of healing using an integrated polarized light system. Results showed that the number of cycles to failure decreased dramatically (37-fold, p<0.005) due to injury, but increased throughout healing, ultimately recovering after 6 weeks. The tangent stiffness, hysteresis, and dynamic modulus did not improve with healing (p<0.005). Linear regression analysis was used to determine relationships between mechanical and structural properties. Of tendon structural properties, the apparent birefringence was able to best predict dynamic modulus (R(2)=0.88-0.92) throughout healing and fatigue life. This study reinforces the concept that fatigue loading is a sensitive metric to assess tendon healing and demonstrates potential structural metrics to predict mechanical properties.

Metal-on-Metal vs Conventional Total Hip Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Metal-on-metal (MOM) hip articulations represent a potential alternative to conventional metal-on-polyethylene total hip arthroplasty (THA). We performed a systematic review of the peer-reviewed literature in search of studies comparing MOM with conventional primary THA with regard to functional outcomes, radiographic outcomes, and complication rates. Four Level I randomized controlled trials remained following our screening process. The data published in these studies were extracted and aggregated using a Mantel-Haenszel cumulative fixed effects meta-analysis. We found no significant difference between MOM and conventional THA with regard to functional outcomes as measured by Harris hip scores and radiographic outcomes as measured by radiolucent lines. Patients with MOM THA did however demonstrate a 3.37 times greater complication rate (1.57, 7.26). In light of the lack of superiority, the increased complication rate, the greater cost, and the potential for adverse medical consequences associated with MOM THA, these bearing surfaces should be used with caution.

Propionibacterium acnes infection in shoulder arthroscopy patients with postoperative pain

BACKGROUND Recent studies have identified Propionibacterium acnes as the causal organism in an increasing number of postoperative shoulder infections. Most reports have found a high rate of P acnes infection after open surgery, particularly shoulder arthroplasty. However, there are limited data regarding P acnes infections after shoulder arthroscopy. MATERIALS AND METHODS We prospectively collected data on all shoulder arthroscopies performed by the senior author from January 1, 2009, until April 1, 2013. Cultures were taken in all revision shoulder arthroscopy cases performed for pain, stiffness, or weakness. In addition, 2 cultures were taken from each of a cohort of 32 primary shoulder arthroscopy cases without concern for infection to determine the false-positive rate. RESULTS A total of 1,591 shoulder arthroscopies were performed during this period, 68 (4.3%) of which were revision procedures performed for pain, stiffness, or weakness. A total of 20 revision arthroscopies (29.4%) had positive culture findings, and 16 (23.5%) were positive for P acnes. In the control group, 1 patient (3.2%) had P acnes growth. CONCLUSIONS The rate of P acnes infection in patients undergoing revision shoulder arthroscopy is higher than previously published and should be considered in cases characterized by refractory postoperative pain and stiffness.

Level of evidence of presentations at american academy of orthopaedic surgeons annual meetings

BACKGROUND The American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting is a major international forum for scientific exchange and education. The purpose of this study was to evaluate the level of evidence of papers and posters presented at the 2001, 2004, 2007, and 2010 AAOS meetings to determine trends in the quality of study designs between the years 2001 and 2010. METHODS Abstracts for AAOS presentations from 2001 (288 papers and 468 posters), 2004 (290 papers and 466 posters), 2007 (525 papers and 541 posters), and 2010 (720 papers and 569 posters) were independently evaluated by three reviewers. The level of evidence of each presentation was determined based on the AAOS classification system. The results were subdivided according to orthopaedic subspecialty and type of presentation. RESULTS In subsequent years, there was a substantial increase in the percentage of Level I studies (2% in 2001, 3% in 2004, 5% in 2007, and 7% in 2010), Level II studies (15% in 2001, 18% in 2004, 23% in 2007, and 29% in 2010), and Level III studies (22% in 2001, 26% in 2004, 29% in 2007, and 33% in 2010), with a concomitant decrease in the percentage of Level IV studies (62% in 2001, 54% in 2004, 43% in 2007, and 31% in 2010). Overall, there was a significant nonrandom improvement in the level of evidence of presentations over the study period (p < 0.001). This trend was consistent across all orthopaedic subspecialties and in both the paper and the poster subgroups. CONCLUSIONS The level of evidence of studies presented at the AAOS Annual Meeting is steadily increasing, which signifies a mark of continual improvement in the quality of the scientific program.

Level of Evidence: Does It Change the Rate of Publication and Time to Publication of American Academy of Orthopaedic Surgeons Presentations?

BACKGROUND Presentations at the Annual Meetings of the American Academy of Orthopaedic Surgeons (AAOS) are often used to guide clinical practice, although many corresponding manuscripts are not published. The purpose of this study was to determine the relationship between level of evidence, rate of publication, and time to publication of presentations from an AAOS Annual Meeting. METHODS A comprehensive literature search for all 756 studies (288 papers and 468 posters) presented at the 2001 AAOS Annual Meeting was performed to determine which of these studies were ultimately published in the peer-reviewed literature. The corresponding AAOS abstracts were each assigned a level of evidence (LOE) with use of a consensus approach and The Journal of Bone and Joint Surgery (JBJS)/AAOS LOE classification system. The rate of publication and mean time to publication for each LOE was then calculated and compared. RESULTS The overall publication rate for the 2001 AAOS paper and poster presentations was 49% after five years, and 58% after ten years. At five and ten-year intervals, respectively, 77% and 85% of Level I presentations were published; 69% and 74% of Level II presentations were published; 58% and 66% of Level III presentations were published; and 39% and 51% of Level IV presentations were published. Overall, there was a significant nonrandom difference in publication rates at both five and ten years by LOE (p values of ≤0.001). Level I and II presentations were 2.9 times more likely than Level III and IV presentations to be published after five years (95% confidence interval 1.9 to 4.5), and 2.5 times more likely to be published after ten years (95% confidence interval 1.6 to 4.0). A similar association between LOE and five and ten-year publication rates was observed for both the paper and poster subgroups. The mean time to publication was 0.9 years for Level I studies, 1.4 years for Level II studies, 2.1 years for Level III studies, and 2.7 years for Level IV studies. CONCLUSIONS The LOE of AAOS presentations is positively related to rate of publication and inversely related to time to publication. Presentations with higher levels of evidence are published in the peer-reviewed literature at a greater and faster rate than those with lower levels of evidence.

Surgical fixation of extra-articular distal humerus fractures with a posterolateral plate through a triceps-reflecting technique

BACKGROUND Surgical management of extra-articular distal humerus fractures results in predictable fracture alignment. Open reduction and internal fixation also decrease the soft tissue complications and frequent follow-up required with functional bracing. A triceps-reflecting posterior approach provides excellent exposure to the humerus and minimizes trauma to the triceps. An anatomically precontoured plate on the posterolateral surface of the humerus provides stable fixation of these injuries and is placed directly through the interval developed by the triceps-reflecting approach. METHODS We retrospectively reviewed the trauma databases at 2 level I academic trauma institutions during a 5-year period for all patients with an extra-articular distal humerus fracture treated with a triceps-reflecting approach and an anatomically precontoured posterolateral distal humerus plate. Patient and fracture characteristics were recorded, as were QuickDASH functional scores and visual analog scale scores for pain, function, and quality of life. RESULTS Forty patients were eligible for our study. Average follow-up was 88 weeks. Thirty-eight (95%) patients went on to union. Seven (20%) patients required a secondary procedure. The average QuickDASH score was 17.5 (range, 2.6-56.8). The average visual analog scale scores were 1.9 (range, 0-7) for pain, 2.3 (range, 0-8) for function, and 1.6 (range, 0-5) for quality of life. Thirty-five (87.5%) patients reported satisfaction with the outcome of their surgery. DISCUSSION Surgical fixation of extra-articular distal humerus fractures through a triceps-reflecting approach with an anatomically precontoured posterolateral distal humerus plate results in predictable osseous union and overall excellent functional results for patients with this injury.

Returning to overuse activity following a supraspinatus and infraspinatus tear leads to joint damage in a rat model

Large rotator cuff tears (supraspinatus and infraspinatus) are common in patients who perform overhead activities (laborers, athletes). In addition, following large cuff tears, these patients commonly attempt to return to pre-injury activity levels. However, there is a limited understanding of the damaging effects on the uninjured joint tissues when doing so. Therefore, the objective of this study was to investigate the effect of returning to overuse activity following a supraspinatus and infraspinatus tear on shoulder function and the structural and biological properties of the intact tendons and glenoid cartilage. Forty rats underwent 4 weeks of overuse followed by detachment of the supraspinatus and infraspinatus tendons and were then randomized into two groups: return to overuse or cage activity. Ambulatory measurements were performed over time and structural and biological properties of the adjacent tendons and cartilage were evaluated. Results demonstrated that animals returning to overuse activity did not have altered shoulder function but despite this, did have altered cartilage and tendon properties. These mechanical changes corresponded to altered transcriptional regulation of chondrogenic genes within cartilage and tendon. This study helps define the mechanical and biological mechanisms leading to joint damage and provides a framework for treating active cuff tear patients.