Periprosthetic joint infection (PJI) represents a complex challenge in orthopaedic surgery associated with substantial morbidity and healthcare expenditures. The debridement, antibiotics, and implant retention (DAIR) protocol is a viable treatment, offering several advantages over exchange arthroplasty. With the evolution of treatment strategies, considerable efforts have been directed towards enhancing the efficacy of DAIR, including the development of a phased debridement protocol for acute PJI management. This article provides an in-depth analysis of DAIR, presenting the outcomes of single-stage, two-stage, and repeated DAIR procedures. It delves into the challenges faced, including patient heterogeneity, pathogen identification, variability in surgical techniques, and antibiotics selection. Moreover, critical factors that influence the decision-making process between single- and two-stage DAIR protocols are addressed, including team composition, timing of the intervention, antibiotic regimens, and both anatomical and implant-related considerations. By providing a comprehensive overview of DAIR protocols and their clinical implications, this annotation aims to elucidate the advancements, challenges, and potential future directions in the application of DAIR for PJI management. It is intended to equip clinicians with the insights required to effectively navigate the complexities of implementing DAIR strategies, thereby facilitating informed decision-making for optimizing patient outcomes.

Cite this article: Bone Joint J 2024;106-B(12):1377–1384.

Aims

Highly cross-linked polyethylene (HXLPE) greatly reduces wear in total hip arthroplasty, compared to conventional polyethylene (CPE). Cross-linking is commonly achieved by irradiation. This study aimed to compare the degree of cross-linking and in vitro wear rates across a cohort of retrieved and unused polyethylene cups/liners from various brands.

Aim. As the number of performed total hip arthroplasties (THA) and total knee arthroplasties (TKA) has increased over the years, revision surgeries are expected to increase as well. Revision surgeries are associated with a longer operating room time, prolonged length of stay (LOS), and more frequent complications. Postoperative hematomas are a major reason for wound healing disturbances and periprosthetic joint infections (PJI). We aimed to systematically assess the use and safety of a microporous polysaccharide hemosphere (MPH) in revision THA and TKA. We focused on the risk reduction of further revision surgeries in case of wound healing disorders and hematoma, transfusion of packed red blood cells (PRBC), loss of hemoglobin (hb) and mean LOS following the use of MPH. Method. Our prospective study includes 89 patients who underwent revision surgery after THA and TKA with application of MPH and were compared to 102 patients who did not receive MPH and underwent revision surgery after THA and TKA. Five grams of MPH. 1. were applied periarticular before fascia closure and to the subcutaneous soft tissue. The follow-up was conducted in daily clinical visits during the inpatient stay and three months postoperatively in our outpatient clinic. Repeated revision surgery was performed in case of prolonged secretion (>10 days) or clinical suspicion of infection. After matching the cohorts the outcomes were statistically analyzed using paired methods. Results. A significantly lower odds ratio for repeat revisions was found for the MPH cohort (OR=0.312; 95%-CI 0.090, 0.893; p=0.027). Differences between pre- and postoperative hb levels, LOS and transfusions of PRBC did not reach significance. No intra- or postoperative complications to MPH occurred. Moreover, no infection relapse occurred after applying MPH. Conclusions. Routine use of MPH in revision arthroplasty management after TKA and THA appears to be safe and an effective way to support hemostasis, with no observed adverse events related to MPH use. There were noticeably less hematomas and revision surgeries in the MPH group. 1. Arista BD, Franklin Lakes, NJ, USA

Understanding spinopelvic mechanics is important for the success of total hip arthroplasty (THA). Despite significant advancements in appreciating spinopelvic balance, numerous challenges remain. It is crucial to recognize the individual variability and postoperative changes in spinopelvic parameters and their consequential impact on prosthetic component positioning to mitigate the risk of dislocation and enhance postoperative outcomes. This review describes the integration of advanced diagnostic approaches, enhanced technology, implant considerations, and surgical planning, all tailored to the unique anatomy and biomechanics of each patient. It underscores the importance of accurately predicting postoperative spinopelvic mechanics, selecting suitable imaging techniques, establishing a consistent nomenclature for spinopelvic stiffness, and considering implant-specific strategies. Furthermore, it highlights the potential of artificial intelligence to personalize care.

Cite this article: Bone Joint J 2024;106-B(11):1206–1215.

Aims

The prevalence of obesity is increasing substantially around the world. Elevated BMI increases the risk of complications following total hip arthroplasty (THA). We sought to evaluate trends in BMI and complication rates of obese patients undergoing primary THA over the last 30 years.

Aims. The outcomes of patients with unexpected positive cultures (UPCs) during revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unknown. The objectives of this study were to establish the prevalence and infection-free implant survival in UPCs during presumed aseptic single-stage revision THA and TKA at mid-term follow-up. Methods. This study included 297 patients undergoing presumed aseptic single-stage revision THA or TKA at a single treatment centre. All patients with at least three UPCs obtained during revision surgery were treated with minimum three months of oral antibiotics following revision surgery. The prevalence of UPCs and causative microorganisms, the recurrence of periprosthetic joint infections (PJIs), and the infection-free implant survival were established at minimum five years’ follow-up (5.1 to 12.3). Results. Of the 297 patients undergoing aseptic revisions, 37 (12.5%) had at least three UPCs obtained during surgery. The UPC cohort included 23 males (62.2%) and 14 females (37.8%), with a mean age of 71.2 years (47 to 82). Comorbidities included smoking (56.8%), hypertension (48.6%), diabetes mellitus (27.0%), and chronic renal impairment (13.5%). The causative microorganisms included Staphylococcus epidermidis (49.6%), Bacillus species (18.9%), Micrococcus species (16.2%), and Cutibacterium acnes (16.2%). None of the study patients with UPCs developed further PJIs or required further surgical intervention during follow-up. Conclusion. The prevalence of UPCs during presumed aseptic revision THA and TKA was 12.5%. The most common causative microorganisms were of low virulence, and included S. epidermidis, Bacillus species, Micrococcus species, and C. acnes. Microorganism-specific antibiotic treatment for minimum three months’ duration of UPCs in presumed aseptic revision arthroplasty was associated with excellent infection-free implant survival at mid-term follow-up. Cite this article: Bone Jt Open 2024;5(10):832–836

Aims

Limited implant survival due to aseptic cup loosening is most commonly responsible for revision total hip arthroplasty (THA). Advances in implant designs and materials have been crucial in addressing those challenges. Vitamin E-infused highly cross-linked polyethylene (VEPE) promises strong wear resistance, high oxidative stability, and superior mechanical strength. Although VEPE monoblock cups have shown good mid-term performance and excellent wear patterns, long-term results remain unclear. This study evaluated migration and wear patterns and clinical and radiological outcomes at a minimum of ten years’ follow-up.

Aims

Our aim was to estimate the total costs of all hospitalizations for treating periprosthetic joint infection (PJI) by main management strategy within 24 months post-diagnosis using activity-based costing. Additionally, we investigated the influence of individual PJI treatment pathways on hospital costs within the first 24 months.

The October 2024 Research Roundup³⁶⁰ looks at: Fracture risk among stroke survivors according to post-stroke disability status and stroke type; Noise-induced hearing loss: should surgeons be wearing ear protection during primary total joint replacement?; Intravenous dexamethasone in hip arthroscopy can enhance recovery; Patient-reported outcomes following periprosthetic joint infection of the hip and knee: a longitudinal, prospective observational study; When should surgery take place after weight loss?; Which type of surgery is the hardest physically and mentally?

The October 2024 Hip & Pelvis Roundup³⁶⁰ looks at: Does the primary surgical approach matter when choosing the approach for revision total hip arthroplasty?; Time to achieve the minimal clinically important difference in primary total hip arthroplasty: comparison of anterior and posterior surgical approaches; To scope or not to scope: arthroscopy as an adjunct to PAO does not provide better clinical outcomes at one year than PAO alone; Re-exploring horizons in hip resurfacing: two-year results of a ceramic-on-ceramic hip resurfacing; Association between tranexamic acid and decreased periprosthetic joint infection risk in patients undergoing total hip and knee arthroplasty; Octogenarians fare well: in revision for infection age is not a bar.

This study aimed to verify the hypothesis that an antibiotic loaded hydrogel, defensive antimicrobial coating (DAC), reduces overall complication and infection rates when used for high-risk primary and revision total hip arthroplasty (THA). This was a retrospective study matched cohort study of 238 patients, treated with cementless implants with and without DAC. A sub-group analysis of patients undergoing 2nd stage revision THA for prosthetic joint infection (PJI) was also conducted. Re-infection rates within 2 years, complications necessitating surgical intervention and radiographic analysis for aseptic loosening was assessed. The mean age was 68.3±11.5 years, with 39 (32.8%) Macpherson class A, 64 (53.8%) class B and 16 (13.4%) class C patients. 4 (3.4%) patients in the DAC group developed complications including 1 PJI and 1 delayed wound healing, while 13 (10.9%) patients in the control group developed complications including 5 PJIs and 3 delayed wound healing (p=0.032). PJI rates (p=0.136) and delayed wound healing rates (p=0.337) were not statistically significant. For 2nd stage revision THA for PJI there were 86 patients in the DAC group and 45 in the control group. 1 (1.2%) patient in the DAC group developed complications with no recurrences of infection or delayed wound healing, while 10 (22.2%) patients in the control group developed complications including 4 recurrent PJI and 1 delayed wound healing (p=0.003). Recurrent PJI rates were statistically significant (p=0.005) while delayed wound healing rates were not (p=0.165). Patients treated with DAC also had lower rates of aseptic loosening (0% vs 6.7%; p=0.015). Antibiotic impregnated hydrogel coatings on cementless implants showed decreased complication rates after complex primary or revision THA. In 2nd stage revision THA for PJI, it was associated with reduced risk of re-infection and aseptic loosening

Dislocation is a serious complication to be avoided in total hip arthroplasty (THA) and its incidence risk increases in revision surgery. Combined anteversion (CA) of the cup and stem is a concept for appropriate implant positioning; however, the effect of functional changes in femoral rotation has not been well investigated. The aim of this study was to investigate whether functional CA, considering femoral rotation, is associated with dislocation in patients undergoing revision THA. Seventy-three patients who underwent revision THA and had at least one year of follow-up with pre- and postoperative supine CT imaging were included. Cup and stem were placed with a target combined angle of 37.3° using Widmer's formula. Anatomical and functional CA was calculated postoperatively using the following formula: Anatomical CA: cup anteversion + 0.7 × anatomical stem anteversion; Functional CA: cup anteversion + 0.7 × (anatomical stem anteversion + femoral rotation). Patient demographics, cup and stem angles, CA and their relationship to dislocation were statistically evaluated. Dislocation was observed in 12 patients. In these dislocated cases, there were no significant differences in cup angle, stem angle and anatomical CA compared to non-dislocated cases. However, dislocated cases showed significantly higher values of functional CA [52.7 ± 17.5° (range, 5.9–69.3) vs. 36.0 ± 12.5° (range, 8.6–68.8), p=0.009] and significant deviation from identical CA [17.3 ± 9.6° (range, 2.8–32) vs. 7.5 ± 7.1° (range, 0.1–28.7), p=0.010]. Functional CA considering femoral rotation was associated with dislocation in revision THA patients. This finding suggests that consideration of femoral rotation may be necessary for implant positioning in revision THA

Few surgical techniques to reconstruct the abductor mechanism of the hip have been reported, with outcomes reported only from case reports and small case series from the centres that described the techniques. As in many of our revision THA patients the gluteus maximus was affected by previous repeat posterior approaches, we opted to reconstruct the abductor mechanism using a vastus lateralis to gluteus medius transfer. We report the results of such reconstructions in seven patients, mean age 66 (range, 53–77), five females, presenting with severe abductor deficiency (MRC grade 1–2). Five patients had previous revision THA, two with a proximal femoral replacement, one patient had a primary THA after a failed malunited trochanteric fracture, and one patient had a native hip with idiopathic fatty infiltration of glutei of >90%. All patients had instrumented gait analysis, and surface electromyography (EMG) of the glutei, TFL, and vastus muscles simultaneously before surgery and at each post-op follow-up. Postoperatively, patients were allowed to weight bear as tolerated and were requested to wear an abduction brace for the first six weeks after surgery to protect the transfer. All patients improved after surgery and reached an abductor power of 3 or more. All patients walked without support six months after surgery and were satisfied with the result. Abductor function continued to improve beyond one year of follow-up, and some patients reached an abductor power of 5. EMG demonstrated that the transferred vastus lateralis started firing synchronously with gluteus medius after three months post-surgery, suggesting adaptation to its new function. No knee extension weakness was recorded. One patient complained of lateral thigh numbness and was dissatisfied with the cosmetic look of her thigh after surgery. Our preliminary results are encouraging and comparable with those achieved by the originators of the technique

For over a decade, modular titanium fluted tapered (TFT) stems have demonstrated excellent clinical success for femoral revision total hip arthroplasty (THA) surgery. The aim of this study was to report the short-term outcomes of a novel modern monoblock TFT stem used for revision and complex primary THA with a minimum of 2 years follow-up. We identified 126 patients who received a single monoblock TFT stem - 26 patients for complex THA (failed fracture fixation) and 100 patients for revision THA. The reasons for revision THA included 40 for previous prosthetic joint infection (PJI), 42 for aseptic loosening, 9 for trunnionosis, 9 for periprosthetic fractures. The Paprosky grading for femoral bone loss at the time of surgery and the measured subsidence of femoral stems at 3 months follow-up were determined. We evaluated the number and indications for re-operations. The mean time from surgery was 3.9 years (range 2.0 to 6.9 years). A paired t-test analysis showed significant improvement from pre-operative versus post-operative clinical outcome scores (p<0.001) for HHS (38.76 +/- 15.24vs. 83.42 +/- 15.38), WOMAC (45.6 ± 19.0 vs. 69.9 ± 21.3) and SF-12 Physical component (31.7 ± 8.1 vs. 37.8 ± 11.3) and SF-12 Mental component (48.2 ± 12.2 vs. 51.6 ± 12.5). The Paprosky grading for femoral bone loss was Grade 1 (3.9%), Grade 2 (35.7%), Grade 3A (47.6%), Grade 3B (11.1%) and Grade 4 (1.6%) cases. There were 18 re-operations (14.7%) with 13 for PJI (7 treated with implant retention, 6 treated with a two-staged revision), 4 for instability and one for acetabular aseptic loosening. There were no aseptic failures of the stem. This novel modern monoblock TFT stem provided reliable femoral fixation and has increasingly supplanted the use of modular TFT stems for complex primary and revision surgery in our institution

Short-stem total hip arthroplasty (THA) may have bone sparing properties, which could be advantageous in a younger population with high risk of future revision surgery. We used data from the AOANJRR, LROI and SAR to compare survival rates of primary THA, stems used in the first-time revision procedures as well as the overall survival of first-time revisions between a cohort of short-stem and standard-stem THA. Short-stem THAs (designed as a short stem with mainly metaphyseal fixation) between 2007 and 2021 were identified (n=16,258). A propensity score matched cohort (1:2) with standard THAs in each register was identified (n=32,515). The cohorts were merged into a research dataset. Overall survival at 12 years follow-up was calculated using Kaplan-Meier survival analyses. Stem revisions (short-stem THA n=239, standard-stem THA n=352) were identified. The type of revision stem was classified as standard (<160 mm) or long (>160 mm). The survival rate of all first-time revisions in the two groups was calculated using any type of revision as outcome. The 12 year- overall survival rate (all revisions, all causes) for primary short-stem THAs was 95.3% (CI 94.5–95.9%), which was comparable to 95.2% (CI 94.7–95.7%) for standard-stem THAs. In the short-stem THA group, a standard stem (<160 mm) was more often (59%) used in the first-time revision than in the standard-stem group (47%, p=0.004). The overall survival of the first-time revisions did not differ between cases primarily operated with a short or a standard stem. In our multi-national register study, the overall survival rate of short stems was similar to that of standard stems. In short stem revisions there was a higher likelihood of using a standard-length stem for the revision compared with first-time revisions of standard stems. This finding might indicate bone-sparing properties with short-stemmed THAs

Dislocation following revision THA remains a leading cause of failure. Integrity of the abductor muscles is a major contributor to stability. Large diameter heads (LDH), Dual Mobility (DM) and Constrained Acetabular Liners (CAL) are enhanced stability options but the indication for these choices remains unclear. We assessed an algorithm based on Gluteus Medius (GM) deficiency to determine bearing selection. Default choice with no GM damage was a LDH. GM deficiency with posterior muscle intact received DM and CAL for GM complete deficiency with loss of posterior muscle. Consecutive revision THA series followed to determine dislocation, all-cause re-revision and Oxford Hip Score (OHS). 311 revision THA with mean age 70 years (32–95). At a mean follow-up of 4.8 years overall dislocation rate 4.1% (95%CI 2.4–7.0) and survivorship free of re-revision 94.2% (95%CI 96.3–91.0). Outcomes:. Group 1 - LDH (36 & 40mm) n=164 / 4 dislocations / 7 re-revisions. Group 2 - DM n=73 / 3 dislocations / 4 re-revisions. Group 3 - CAL n=58 / 5 dislocations / 7 re-revisions. Group 4 - Other (28 & 32mm) n=16 / 1 dislocation / no re-revisions. Mean pre-op OHS: 19.6 (2–47) and mean post-op OHS: 33.9 (4–48). Kaplan-Meier analysis at 60 months dislocation-free survival was 96.1% (95% CI: 93.0–97.8). There was no difference between survival distributions comparing bearing choice (p=0.46). Decision making tools to guide selection are limited and in addition soft tissue deficiency has been poorly defined. The posterior vertical fibres of GM have the greatest lateral stabiliser effect on the hip. The algorithm we have used clearly defined indication & implant selection. We believe our outcomes support the use of an enhanced stability bearing selection algorithm

The results of total hip arthroplasty (THA) revisions to correct leg length discrepancy (LLD) are not clear, with only two former limited series (< 25 patients). Therefore, we conducted a retrospective study of THA revisions for LLD to determine: 1) the change in LLD, 2) the function outcomes and whether obtaining equal leg lengths influenced function, 3) the complication and survival rates. This multicenter study included 57 patients: 42 THA revisions for limb shortening and 15 revisions for limb lengthening. LLD was measured on conventional radiographs and EOS. The Oxford-12 and FJS outcome scores were collected and the number of patients achieving the Oxford-12 MCID. The revisions were carried out a mean of 2.8 years after the index THA. The median LLD decreased from 7.5 mm (IQR: [5;12]) to 1 mm (IQR: [0.5;2.5]) at follow-up (p=0.0002). Overall, 55 of 57 patients (96%) had < 5 mm LLD at follow-up and 12 patients (21%) had equal leg lengths. The complication rate was 25%: 12 mechanical complications (8 periprosthetic femoral fractures, 2 stem loosening and 1 cup loosening, 1 dislocation) and 1 periprosthetic infection. The patient satisfaction was high with a median FJS of 79.2/100 and 77% of patients reached the Oxford-12 MCID. Lengthening procedures had significantly worst function than shortening (38% vs 91% of patients achieving the Oxford-12 MCID (p=0.0004)). Survivorship was 85% (95% CI: 77.9 – 92.5) at 2 years and 77% (95% CI: 66.3 – 87.1) at 4.6 years when using re-revision for any reason as the endpoint. When LLD after THA does not respond to conservative management, revision THA should be considered. Although revision THA for LLD improved medium-term functional outcomes with a high patient satisfaction rate, especially for shortening procedures, the complication rate was high, particularly related to periprosthetic femoral fracture

This meta analysis address the relationship between infection developing after total hip arthroplasty (THA) and heterotopic ossification (HO). To identify the gaps in available knowledge, we screened for full-length peer-reviewed research articles listed in PubMed, Embase, and Web of Science over the past 20 years. The following search terms and Boolean operators were used: heterotopic ossification AND infection AND (hip replacement OR hip arthroplasty). The search resulted in the identification of as few as 14 articles describing periprosthetic joint infection (PJI) and HO after THA. Data summarized from 6 studies suitable for further meta-analysis yielded a cumulative sample size of 753 observations, with 186 recorded events of HO. The pooled RR was estimated at 2.22 (95% CI: 1.00 to 4.91, p = 0.0497), suggesting a more than twofold risk of HO compared to the group without PJI. In conclusion, there is a clear association between a higher risk of HO and PJI. Basic research findings support the hypothesis that bacterial pathogen-associated molecular patterns (PAMPs) can lead to osteogenesis through a toll-like receptor (TLR) and nuclear factor kappa B (NF-κB) pathway in the course of HO development. Together, these results suggest that HO prophylaxis should always be prescribed in PJI after THA. Moreover, during revisions following THA for presumed non-septic reasons, the presence of HO warrants consideration for infection, as there is a potential heightened risk of pathologic ossification induced by PAMPs. Keywords: heterotopic ossification; total hip arthroplasty; total hip replacement; periprosthetic joint infection; bacteria. Authors Ł. Pulik and P. Łęgosz contributed equally to this work

The August 2024 Knee Roundup³⁶⁰ looks at: Calcification’s role in knee osteoarthritis: implications for surgical decision-making; Lower complication rates and shorter lengths of hospital stay with technology-assisted total knee arthroplasty; Revision surgery: the hidden burden on surgeons; Are preoperative weight loss interventions worthwhile?; Total knee arthroplasty with or without prior bariatric surgery: a systematic review and meta-analysis; Aspirin triumphs in knee arthroplasty: a decade of evidence; Efficacy of DAIR in unicompartmental knee arthroplasty: a glimpse from Oxford.

Aims

Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age.