Subsequent total joint arthroplasty: Are we learning from the first stage?

BACKGROUND

With the increasing incidence of total joint arthroplasty (TJA), there is a desire to reduce peri-operative complications and resource utilization. As degenerative conditions progress in multiple joints, many patients undergo multiple procedures.

AIM

To determine if both physicians and patients learn from the patient's initial arthroplasty, resulting in improved outcomes following the second procedure.

METHODS

The institutional database was retrospectively queried for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients with only unilateral THA or TKA, and patients undergoing same-day bilateral TJA, were excluded. Patient demographics, comorbidities, and implant sizes were collected at the time of each procedure and patients were stratified by first vs second surgery. Outcome metrics evaluated included operative time, length of stay (LOS), disposition, 90-d readmissions and emergency department (ED) visits.

RESULTS

A total of 642 patients, including 364 undergoing staged bilateral TKA and 278 undergoing bilateral THA, were analyzed. There was no significant difference in demographics or comorbidities between the first and second procedure, which were separated by a mean of 285 d. For THA and TKA, LOS was significantly less for the second surgery, with 66% of patients having a shorter hospitalization (P < 0.001). THA patients had significantly decreased operative time only when the same sized implant was utilized (P = 0.025). The vast majority (93.3%) of patients were discharged to the same type of location following their second surgery. However, when a change in disposition was present from the first surgery, patients were significantly more likely to be discharged to home after the second procedure (P = 0.033). There was no difference between procedures for post-operative readmissions (P = 0.438) or ED visits (P = 0.915).

CONCLUSION

After gaining valuable experience recovering from the initial surgery, a patient's perioperative outcomes are improved for their second TJA. This may be the result of increased confidence and decreased anxiety, and it supports the theory that enhanced patient education pre-operatively may improve outcomes. For the surgical team, the second procedure of a staged THA is more efficient, although this finding did not hold for TKA.

A simple liquid state 1H NMR measurement to directly determine the surface hydroxyl density of porous silica

Silica is widely used in industrial applications and its performance is partially decided by its surface hydroxyl density α_OH. Here we report a quick, simple liquid ¹H NMR method to determine α_OH using a benchtop ¹H NMR spectrometer. The results show excellent agreement with the literature with an α_OH range from 4.16 to 6.56 OH per nm².

Next-generation sequencing not superior to culture in periprosthetic joint infection diagnosis

AIMS

Use of molecular sequencing methods in periprosthetic joint infection (PJI) diagnosis and organism identification have gained popularity. Next-generation sequencing (NGS) is a potentially powerful tool that is now commercially available. The purpose of this study was to compare the diagnostic accuracy of NGS, polymerase chain reaction (PCR), conventional culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al in the diagnosis of PJI.

METHODS

In this retrospective study, aspirates or tissue samples were collected in 30 revision and 86 primary arthroplasties for routine diagnostic investigation for PJI and sent to the laboratory for NGS and PCR. Concordance along with statistical differences between diagnostic studies were calculated.

RESULTS

Using the MSIS criteria to diagnose PJI as the reference standard, the sensitivity and specificity of NGS were 60.9% and 89.9%, respectively, while culture resulted in sensitivity of 76.9% and specificity of 95.3%. PCR had a low sensitivity of 18.4%. There was no significant difference based on sample collection method (tissue swab or synovial fluid) (p = 0.760). There were 11 samples that were culture-positive and NGS-negative, of which eight met MSIS criteria for diagnosing infection.

CONCLUSION

In our series, NGS did not provide superior sensitivity or specificity results compared to culture. PCR has little utility as a standalone test for PJI diagnosis with a sensitivity of only 18.4%. Currently, several laboratory tests for PJI diagnosis should be obtained along with the overall clinical picture to help guide decision-making for PJI treatment. Cite this article: Bone Joint J 2021;103-B(1):26-31.

A Novel Technique for Creating an Articulating Cement Spacer for Ankle Prosthetic Joint Infections

Total ankle arthroplasty has been increasing as a treatment for end-stage ankle arthritis. With this increase, the incidence of total ankle prosthetic infections will also increase. Treatment of these infections depends on the duration of symptoms and whether the infection is acute or chronic in presentation. The treatment of choice for chronic infections is a 2-stage procedure, the removal of implants and placement of a static cement spacer. We describe a technique for creating an articulating antibiotic cement spacer through an anterior approach in a patient with an infected total ankle arthroplasty. The articulating antibiotic cement spacer allows high doses of local antibiotics, decreases soft tissue contractures, and allows continued motion of the joint.

Dislocation rate increases with bariatric surgery before total hip arthroplasty

INTRODUCTION

Annually in the USA, 113,000 patients with refractory obesity undergo bariatric surgery (BS), and a subset does so in order to lower body mass index to become a more desirable total hip arthroplasty (THA) candidate. This study aims to evaluate THA risk with and without bariatric surgery.

METHODS

12,160 patients were identified in a claim-based review of the entire Medicare database with ICD-9 codes to identify patients in three groups. Patients who underwent BS prior to THA (Group I: 1,545 experimental group) and two control groups that did not undergo BS but had either a body mass index >40 (Group II: 6,918 bariatric control) or <25 (Group III: 3,697 normal weight control). Preoperative demographics/comorbidities and short-term medical (30 day) and long-term surgical (90-day and 2-year) complications were evaluated.

RESULTS

Group I had female predominance, youngest age, and highest incidence of: deficiency anaemia, cardiovascular disease, liver disease, diabetes, polysubstance abuse, psychiatric disorders and smoking. At 2 years, Group I had approximately twice the dislocation and revision risk compared to both Groups II and III; Groups I and II had over four times the risk of infection and wound complications compared to Group III.

CONCLUSION

In the Medicare population, these patients continue to have complication rates similar to and sometimes greater than obese patients with no prior bariatric surgery. Greater dislocation risk is possibly due to ligamentous laxity related to decreased collagen/elastin and/or component malposition due to intraoperative visualisation challenges.