Survivorship of the fixed-bearing medial unicompartmental knee arthroplasty: mean 14-year follow-up in a single medical center.

BACKGROUND: This study aimed to report the long-term survival of fixed-bearing medial unicompartmental knee arthroplasty (UKA) with a mean of 14-year follow-up, and to determine possible risk factors of failure. METHODS: We retrospectively evaluated 337 fixed-bearing medial UKAs implanted between 2003 and 2014. Demographic and radiographic parameters were measured, including pre-operative and post-operative anatomical femorotibial angle (aFTA), posterior tibial slope (PTS), and anatomical medial proximal tibial angle (aMPTA). Multivariate logistic regression analysis was applied to figure out risk factors. RESULTS: The mean follow-up time was 14.0 years. There were 32 failures categorized into implant loosening (n = 11), osteoarthritis progression (n = 7), insert wear (n = 7), infection (n = 4), and periprosthetic fracture (n = 3). Cumulative survival was 91.6% at 10 years and 90.0% at 15 years. No statistically significant parameters were found between the overall survival and failure groups. Age and hypertension were significant factors of implant loosening with odds ratio (OR) 0.909 (p = 0.02) and 0.179 (p = 0.04) respectively. In the insert wear group, post-operative aFTA and correction of PTS showed significance with OR 0.363 (p = 0.02) and 0.415 (p = 0.03) respectively. Post-operative aMPTA was a significant factor of periprosthetic fracture with OR 0.680 (p < 0.05). CONCLUSIONS: The fixed-bearing medial UKA provides successful long-term survivorship. Tibial component loosening is the major cause of failure. Older age and hypertension were factors with decreased risk of implant loosening.

Femoral Coronal Malalignment is Associated With Failure in Mobile-Bearing Medial Unicompartmental Knee Arthroplasty.

BACKGROUND: Femur-first (FF) technique for mobile-bearing medial unicompartmental knee arthroplasty (UKA) has been described as an alternative to tibia-first (TF) technique. The aim of this study was to compare the radiographic results in UKAs using FF or TF techniques and their influence on failure rates. METHODS: We retrospectively reviewed 288 UKAs with a minimum 2-year follow-up. There were 147 knees in the TF and 141 knees in the FF cohorts. Alignment parameters and overhang were assessed as outliers and far outliers. The mean follow-up was 6 years (range, 2 to 16), the mean age was 63 years (range, 27 to 92), and 45% of patients were women. Univariate and multivariate statistical analyses were carried out with Cox regression models. RESULTS: There were 13 and 6 revisions in the TF and FF cohorts, respectively. The FF had lower rates of femoral coronal alignment (FCA) or femoral sagittal alignment outliers compared to the TF (5.7% versus 19%, P = .011). Tibial coronal alignment and tibial sagittal alignment did not significantly differ between the techniques (22.7% in FF versus 29.9% in TF, P = .119). Overhang outliers did not differ significantly between the groups. Younger age was associated with a higher revision rate (P = .006), while FF versus TF, sex, body mass index, and postoperative mechanical axis did not show statistically significant associations. In multivariate analysis, FCA outliers and younger age were significantly associated with revision. CONCLUSIONS: The FF technique in mobile-bearing UKA resulted in fewer FCA outliers compared to TF. Despite improved knee alignment with the FF technique, FCA outliers and younger age were associated with a higher revision rate, independent of technique.

Total knee replacement with an accelerometer-based, hand-held navigation system improves knee alignment: reliable in all patients.

BACKGROUND: Achieving adequate alignment has traditionally been an important goal in total knee arthroplasty to achieve long-term implant survival. While accelerometer-based hand-held navigation systems (ABN) has been introduced as a way to achieve alignment, there is a limited body of evidence on its accuracy, especially in patients under 65 years with differing etiologies for knee arthritis. This study aimed to assess the precision of a specific ABN system in restoring the mechanical axis and report surgical variables and complications, with particular attention to younger patients. METHODS: We conducted a retrospective review of 310 primary TKA performed with ABN from May 2016 to February 2021. The mean patient age was 67.4 (SD 8.9) years, with 43% under 65 years and mean body mass index of 33.2 (SD 6.8). The average surgical time was 96.8 min (57-171) and the average follow-up was 3.3 years (1.9-6.7). Data regarding length of stay, pain, range of motion (ROM), complications, and reinterventions were collected from the institutional joint arthroplasty registry and the medical records. Preoperative mechanical axis measurements and postoperative radiological data, including mechanical axis, component alignment and mechanical alignment outliers were analyzed. RESULTS: The mean preoperative mechanical axis was 175.4° (SD 7.6), with 248 knees (80%) in preoperative varus. The mean postoperative mechanical axis was 179.5° (SD 1.96) with 98% of knees falling within ± 3° of the neutral mechanical axis. Only 6 knees (2 varus, 4 valgus) fell outside the ± 3° range. And 3 knees (1 varus, 2 valgus) fell outside the ± 5° range. In the sagittal plane, 296 knees (95.5%) knees were within ± 3° of goal of 3 degrees of femoral flexion and 302 (97.4%) knees were within ± 2° of goal 1° of slope for tibial component. Far outliers (alignment outside ± 5° of targeted position) were found in 3 knees. Factors such as posttraumatic arthrosis, previous surgery, presence of retained hardware, and age below 65 years were not associated with increase in alignment outliers and far outliers. No complications related to the navigation system were observed. There were 22 complications and 20 reoperations, including 2 revisions for periprosthetic joint infection and 1 revision for flexion instability. Patients that required knee manipulation achieved an ultimate flexion of 110° (SD 14.1). CONCLUSIONS: The ABN system proved to be user-friendly and accurate in reducing alignment outliers in both coronal and sagittal planes in all patient populations. It offers a straightforward navigation solution while preserving surgeon autonomy and the use of traditional surgical tools. These findings advocate for the integration of this navigation system as a valuable tool to enhance the precision of TKA surgery in all patient groups.

Making the cut: a technical note and literature review of Bernese periacetabular osteotomy techniques with special attention to ischial osteotomy initiation and completion with an inside to anterior curved osteotomy.

Periacetabular osteotomy includes a fluoroscopy-guided ischial cut without direct visualization. Previously described techniques include a mediolateral ischial cortex cut, which is associated with the risk of injuring nearby nerves. Another drawback of that technique is the difficulty connecting an ischial cortex cut with a retroacetabular cut due to orthogonal nature of the osteotomy. In general, an additional cut from medial to lateral is required. The present study aimed to describe a technique that eliminates those problems due to use of only a central cut of the ischium and the curved nature of the osteotomy.

Clinical outcomes of various types of revision surgeries after unicompartmental knee arthroplasty failure.

PURPOSE: The advantages of unicompartmental knee arthroplasty (UKA) have led to the procedure being increasingly performed worldwide. However, revision surgery is required after UKA failure. According to the literature review, the choice of implant in revision surgery remains a debatable concern. This study analyzed the clinical results of different types of prostheses used in treating failed UKA. MATERIALS AND METHODS: This is a retrospective review of 33 failed medial UKAs between 2006 and 2017. Demographic data, failure reason, types of revision prostheses, and the severity of bone defects were analyzed. The patients were classified into three groups: primary prosthesis, primary prosthesis with a tibial stem, and revision prosthesis. The implant survival rate and medical cost of the procedures were compared. RESULTS: A total of 17 primary prostheses, 7 primary prostheses with tibial stems, and 9 revision prostheses were used. After a mean follow-up of 30.8 months, the survival outcomes of the three groups were 88.2%, 100%, and 88.9%, respectively (P = 0.640). The common bone defect in tibia site is Anderson Orthopedic Research Institute [AORI] grade 1 and 2a (16 versus 17). In patients with tibial bone defects AORI grade 2a, the failure rates of primary prostheses and primary prostheses with tibial stems were 25% and 0%, respectively. CONCLUSIONS: The most common cause for UKA failure was aseptic loosening. The adoption of a standardized surgical technique makes it easier to perform revision surgeries. Primary prostheses with tibial stems provided higher stability, leading to a lower failure rate due to less risk of aseptic loosening in patients with tibial AORI grade 2a. In our experience, we advise surgeons may try using primary prostheses in patients with tibial AORI grade 1 and primary prostheses with tibial stems in patients with tibial AORI grade 2a.

Femur-First Technique for Mobile Bearing Unicompartmental Knee Arthroplasty Results in Decreased Implant Variability and Early Improvements in Function and Survivorship.

BACKGROUND: Higher failure rates of unicompartmental knee arthroplasty (UKA) are seen with lower surgical volume. Surgical techniques that introduce less variability improving implant positioning may lead to improved survivorship. A femur-first (FF) technique has been described, but survivorship data compared to traditional tibia-first (TF) technique are under-reported. We report the results of mobile-bearing UKA using the FF technique compared to the TF technique with emphasis on implant position and survivorship. METHODS: A total of 430 UKAs were performed by a single surgeon between 2007 and 2020. After 2012, there were 141 consecutive UKAs performed with the FF technique which were compared with 147 consecutive UKAs prior. Mean follow-up was 6 years (range, 2 to 13 years), average age was 63 years (range, 23 to 92 years), and there were 132 women. Postoperative radiographs were reviewed to determine implant positioning. Survivorship analyses were performed using Kaplan-Meier curves. RESULTS: The FF resulted in significantly thinner polyethylene (3.4 ± 0.7 mm versus 3.7 ± 0.9 mm) (P = .002) and 4 mm or less bearing thickness in 94% of cases. At 5 years, there was an early trend toward improved survivorship free from component revision (98% for the FF group and 94% for the TF [P = .35]). The FF cohort had higher Knee Society Functional scores at final follow-up (P < .001). CONCLUSION: Compared to traditional TF technique, the FF was more bone-preserving and improved radiographic positioning. The FF technique is an alternative method for mobile-bearing UKA and was associated with an improvement in implant survivorship and function.

Risk Factors for Treatment Failure in Patients Who Have Knee Periprosthetic Joint Infection Treated With Two-Stage Exchange Arthroplasty as Well as Their Fate.

BACKGROUND: Two-stage exchange arthroplasty is considered the gold standard treatment for chronic periprosthetic joint infection (PJI). However, there is a scarcity of research investigating the major risk factors for infection recurrence and the prognosis after infection recurrence. METHODS: This study included 203 patients who underwent 2-stage exchange arthroplasty between June 22, 2010 and January 24, 2017. The need of reoperation for infection-related or PJI-related mortality was considered treatment failure. Participant age, gender, body mass index, comorbidities, culture results, length of hospital stay, cause of treatment failure, operative procedure, and fate were analyzed. RESULTS: Fifty-three patients experienced treatment failure (26.1%). Mean follow-up was 63 months (range, 26-103). Based on the multivariate analyses, risk factors for treatment failure included men and positive intraoperative culture during reimplantation. Recurrent infection was most commonly caused by Staphylococcus aureus (32.1%, 17/53), and new microorganisms caused recurrent infection in 34 of 53 (64.2%) patients. In 44 patients who had treatment failure, debridement, antibiotic therapy, irrigation, and retention of prosthesis (DAIR) performed within 6 months of reimplantation and at <3 weeks from symptom onset resulted in a significantly higher success rate than the use of other DAIR protocols (P = .031). CONCLUSION: Men and positive intraoperative culture are major risk factors for 2-stage exchange arthroplasty failure in patients who have knee PJI. Recurrent infection in these patients is usually caused by new microorganisms. DAIR within 6 months of reimplantation and at <3 weeks from symptom onset results in good outcomes in these patients.

Application of structural allogenous bone graft in two-stage exchange arthroplasty for knee periprosthetic joint infection: a case control study.

BACKGROUND: Knee prosthetic joint infection (PJI) is a common but devastating complication after knee arthroplasty. The revision surgeries for knee PJI may become more challenging when it is associated with large bone defects. The application of structural bone allograft in knee revision surgeries with large bone defects is not a new technique. However, there is a lack of literature reporting its efficacy in PJI cases. This study aimed to investigate the outcome of structural fresh frozen allogenous bone grafts in treating patients in knee PJI with large bone defects. METHODS: We performed a retrospective cohort analysis of knee PJI cases treated with two-stage exchange arthroplasty at our institution from 2010 to 2016. 12 patients with structural allogenous bone graft reconstructions were identified as the study group. 24 patients without structural allograft reconstructions matched with the study group by age, gender, and Charlson comorbidity index were enrolled as the control group. The functional outcome of the study group was evaluated with the Knee Society Score (KSS). Treatment success was assessed according to the Delphi-based consensus definition. The infection relapse rate and implant survivorship were compared between groups. RESULTS: Revision knees with structural allograft presented excellent improvement in the KSS (33.1 to 75.4). There was no significant difference between infection relapse-free survival rate and prosthesis survival rate in the two groups. The 8-year prosthesis survival rate was 90.9% in the study group and 91% in the control group (p = 0.913). The 8-year infection relapse-free survival rate was 80 and 83.3% in the study group and control group, respectively (p = 0.377). CONCLUSION: The structural fresh frozen allogenous bone graft provided an effective way for bone defect reconstruction in knee PJI with an accountable survival rate. Meanwhile, using structural allografts did not increase the relapse rate of infection.

Higher reinfection rate after two-stage revision arthroplasty in patients with refractory diabetes mellitus: a retrospective analysis with a minimum ten-year follow up.

BACKGROUND: Treatment protocols for two-stage revision arthroplasty with diabetes mellitus (DM) have not yet been established. The control of glycated hemoglobin (HbA1c) in two-stage revision arthroplasty is still debated. This study aimed to clarify the importance of preoperative HbA1c levels before each stage of revision arthroplasty and to analyze the risk factors for reinfection. METHODS: Five hundred eighty-eight patients suffered from first-time PJI and was treated in our institute from January 1994 to December 2010 were reviewed. The mean follow-up time was 13.8 (range, 10.2-24.8) years. Patients underwent two-stage revision arthroplasty with DM at presentation were included. The endpoint of the study was reinfection of the revision arthroplasty. Demographic, survivorship, and surgical variables were also analyzed. RESULTS: Eighty-eight patients were identified and grouped by HbA1c level before the first stage surgery: Groups 1 and 2 had HbA1c levels < 7% and ≥ 7%, respectively. Reinfection was identified in 4.55% (2/44) and 18.18% (8/44) of the patients in Groups 1 and 2, respectively. Survivorship analysis revealed correction of the HbA1c before the final stage of revision arthroplasty as an independent factor (p < 0.001). The identified risks for reinfection were HbA1c levels ≥ 7% before final-stage surgery, ≥ 3 stages of revision arthroplasty, and extended-spectrum beta-lactamase (ESBL)-Escherichia coli PJI. CONCLUSION: The HbA1c level before the final stage of revision arthroplasty could affect staged revision arthroplasty outcomes. Therefore, the necessity of postponing the elective final-stage revision arthroplasty procedure for HbA1c control should be further investigated in the future.

Two-stage exchange Arthroplasty for knee Periprosthetic joint infection exhibit high infection recurrence rate in patients with chronic viral hepatitis.

BACKGROUND: Currently, there is little evidence about the outcome of two-stage exchange arthroplasty for the treatment of knee periprosthetic joint infection (PJI) in patients with chronic viral hepatitis. To evaluate it, we set the primary outcome as infection recurrence, and the secondary outcome as the difference between patients diagnosed with hepatitis B virus or hepatitis C virus. PATIENTS AND METHODS: Between June, 2010 and December, 2016, 172 patients with knee PJIs were treated with two-stage exchange arthroplasty at our institute. Treatment success was defined using Delphi-based consensus. These patients were further divided into groups with or without chronic hepatitis. Variables were analyzed, including age, sex, comorbidities, microbiology, and operative methods. Minimum follow-up was 12 months (mean, 35 months; range, 12-85 months). RESULTS: Of the 172 knee PJI patients, 25 were identified with chronic hepatitis. The infection recurrence rate in the hepatitis group (28%, 7 in 25) was significantly higher than that in the non-hepatitis group (9.5%, 14 in 147), p = 0.017. However, there was no significant difference in the infection recurrence rates between patients with HBV (24%, 4 in 16) and HCV (33.3%, 3 in 9). Regarding the outcomes of patients with infection recurrence, 4 of the non-hepatitis patients were treated with the debridement, antibiotic treatment, irrigation, and retention of prosthesis (DAIR) procedure, with a success rate of 75%. The other 17 patients (7 with hepatitis and 10 without) were treated with repeated two-stage exchange arthroplasty with 100% infection elimination rate until the final follow-up. CONCLUSIONS: Knee PJI patients with chronic hepatitis have higher infection recurrence rate after two-stage exchange arthroplasty (28%).

Trend of serum C-reactive protein is associated with treatment outcome of hip Periprosthetic joint infection undergoing two-stage exchange arthroplasty: a case control study.

BACKGROUND: Serum C-reactive protein (CRP) trends are critical for monitoring patients' treatment response following a two-stage exchange arthroplasty for periprosthetic joint infection (PJI) of the hip. However, CRP trends are poorly described in the literature. The primary aim of this study was to identify the relationships between PJI treatment outcomes and our proposed CRP trend definitions, parameters, and microbiological data. The secondary aim was to investigate CRP trends after the occurrence of spacer-related complications. METHODS: We conducted a retrospective review of 74 patients treated with a two-stage exchange protocol for PJI in a tertiary referral joint center between 2014 and 2016. Patients with factors that may affect CRP levels (inflammatory arthritis, concomitant infections, liver and kidney diseases, and intensive care admissions) were excluded. CRP trends were categorized into five types and PJI treatment outcome was defined as "success" or "failure" according to the Delphi criteria. RESULTS: Treatment was successful in 67 patients and failed in 7 patients. Multivariate logistic regression analysis showed that type 5 CRP, defined as serum CRP fluctuation without normalization after first stage surgery (odds ratio [OR]: 17.4; 95% confidence interval [CI]: 2.3-129.7; p = 0.005), and methicillin-resistant Staphylococcus aureus (MRSA; OR: 14.5; 95% CI: 1.6-131.7; p = 0.018) were associated with treatment failure. Spacer-related complications occurred in 18 patients. Of these, 12 had elevated CRP levels at later follow-up, while six had no elevation in CRP levels. CONCLUSIONS: We found that MRSA infection and type 5 CRP were associated with PJI treatment failure.

The Risk Factor and Outcome of Metachronous Periprosthetic Joint Infections: A Retrospective Analysis With a Minimum Ten-Year Follow-Up.

BACKGROUND: Patients with multiple prosthetic joints are at risk of developing periprosthetic joint infections (PJIs). We aimed to determine whether PJI development at one site may lead to infection at another prosthetic joint site and assess the risk factors leading to this subsequent infection. METHODS: We reviewed all cases (294 patients with first-time PJI [159 hips, 135 knees]) with PJI treated at our institute between January 1994 and December 2020. The average follow-up period was 11.2 years (range 10.1-23.2). Patients were included if they had at least one other prosthetic joint at the time of developing a single PJI (96 patients). Patients with synchronous PJI were excluded from the study. The incidence of metachronous PJI was assessed, and the risk factors were determined by comparing different characteristics between patients without metachronous PJI. RESULTS: Of the 96 patients, 19.79% developed metachronous PJI. The identified causative pathogen was the same in 63.16% of the patients. The time to developing a second PJI was 789.84 days (range 10-3386). The identified risk factors were PJI with systemic inflammatory response syndrome, ≥3 stages of resection arthroplasty, and PJI caused by methicillin-resistant Staphylococcus aureus. CONCLUSION: PJI may predispose patients to subsequent PJI in another prosthesis with identified risks. Most causative organisms of metachronous PJI were the same species as those of the first PJI. We believe that bacteremia may be involved in pathogenesis, but further research is required.

Influence of extension stem length and diameter on clinical and radiographic outcomes of revision total knee arthroplasty.

BACKGROUND: Extension stems provide stability to revision total knee arthroplasty (RTKA). Little is known regarding the relationship between stem characteristics and RTKA stability. We aimed to identify the relationship between canal filling ratio (CFR) and aseptic loosening following RTKA. METHODS: We retrospectively reviewed demographics, radiographic parameters, and outcomes associated with RTKA performed between 2008 and 2013 in a tertiary hospital. The inclusion criteria were: revision for aseptic loosening, hybrid fixation, minor bone defect, Zimmer® LCCK prosthesis, and follow-up > 24 months. Using the modified Knee Society radiographic scoring system, radiographic prosthesis loosening was defined as a radiolucent line (RLL) score ≥ 9 on the femoral side or ≥ 10 on the tibial side. We utilized receiver operating characteristic (ROC) curve analysis to evaluate the cutoff value for stem length and diameter in terms of prosthesis loosening or not. Furthermore, CFR-related parameters were analyzed with logistic regression to clarify their relationships with prosthesis loosening. RESULTS: Prosthesis loosening was detected in 17 of 65 patients included. On logistic regression analysis, male sex and severity of the tibial bone defect were associated with loosening. On multivariate analysis, male sex and bone defect severity were associated with loosening on the femoral side, while malalignment was associated with loosening on the tibial side. Protective factors included femoral CFR > 0.85, CFR > 0.7 for > 2 cm, and CFR > 0.7 for > 4 cm, as well as tibial CFR > 0.85. CONCLUSIONS: To minimize loosening post-RTKA, femoral CFR > 0.7 for > 2 cm and tibial CFR > 0.85 are recommended. Risk factors may include male sex, bone defect severity, and malalignment.

Unplanned revision spinal surgery within a week: a retrospective analysis of surgical causes.

BACKGROUND: The need for revision surgery after a spinal surgery can cause a variety of problems, including reduced quality of life for the patient, additional medical expenses, and patient-physician conflicts. The purpose of this study was to evaluate the causes of unplanned revision spinal surgery within a week after the initial surgery in order to identify the surgical issues most commonly associated with unplanned revision surgery. METHODS: We retrospectively reviewed the medical records of all patients at who received a spinal surgery at a regional medical center from July 2004 to April 2011 in order to identify those who required a revision surgery within one week of their initial surgery. Patients were excluded if they received a vertebroplasty, kyphoplasty, or nerve block surgery, because those surgeries are one-day surgeries that do not require hospital admission. In addition, patients with a primary diagnosis of wound infection were also excluded since reoperations for infection control can be expected. RESULTS: The overall incidence of unplanned revision spinal surgery during the time period covered by this review was 1.12% (116/10,350 patients). The most common surgical causes of reoperation were screw malposition (41 patients), symptomatic epidural hematoma (27 patients), and inadequate decompression (37 patients). Screw malposition was the most common complication, with an incidence rate of 0.82%. Screw instrumentation was significantly associated with revision surgery (p = 0.023), which suggests that this procedure carried a greater risk of requiring revision. The mean time interval to reoperation for epidural hematomas was significantly shorter than the intervals for other causes of revision spinal surgery (p < 0.001), which suggests that epidural hematoma was more emergent than other complications. Also, 25.93% of patients who underwent hematoma removal experienced residual sequelae; this percentage was significantly higher than for other surgical causes of revision spinal surgery (p = 0.013). CONCLUSIONS: The results suggest that to avoid the need for reoperation, screw malposition, inadequate decompression, and epidural hematoma are the key surgical complications to be guarded against. Accordingly, adequate decompression, epidural hematoma prevention, and proper pedicle screw placement may help reduce the incidence of revision surgery.

A New Arthroscopic Classification for Chondrolabral Disease in Patients Undergoing Surgery for Developmental Dysplasia of the Hip.

BACKGROUND: Current classification systems for intra-articular pathology intraoperatively have been described for patients with femoroacetabular impingement rather than dysplasia. PURPOSE: To (1) describe intra-articular findings in dysplastic hips undergoing combined hip arthroscopy and periacetabular osteotomy (PAO); (2) propose a new chondrolabral classification system for dysplastic hips based on these findings; and (3) correlate patient-reported outcome measures (PROM) with the newly proposed classification. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 46 hips underwent combined hip arthroscopy and PAO at our institution between September 2013 and December 2014, irrespective of symptoms or radiographic findings. PROMs were evaluated preoperatively and at 2 years postoperatively. At the time of hip arthroscopy, the chondrolabral junction was classified as normal without tear (1 hip, type 1); hypertrophic labrum without chondrolabral disruption (19 hips, type 2); chondrolabral disruption on the articular side, not extending into the capsular side (16 hips, type 3A); chondrolabral disruption extending through the capsular side (3 hips, type 3B); and exposed acetabular subchondral bone (7 hips, type 4). RESULTS: There was a significant difference in postoperative modified Harris Hip Score (mHHS) (P = .020), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores (P = .037), and WOMAC total scores (P = .049) between chondrolabral junction types. Post hoc analyses demonstrated significant differences between type 2 (84.9 ± 12.9) and type 3A (67.8 ± 20.7; P = .198), and between type 2 and type 4 (59.3 ± 24.3; P = .011) in postoperative mHHS scores; and between type 2 (83.9 ± 12.9) and type 3A (68.9 ± 23.7; P = .045) in postoperative WOMAC total scores. In multivariate analysis, chondrolabral type 3 or type 4, age >35 years, and previous surgery were significantly correlated with worse mHHS scores at 2 years. CONCLUSION: This new chondrolabral classification is proposed to describe intra-articular pathology seen during combined hip arthroscopy and PAO, specifically in dysplastic hips. More advanced chondrolabral disease was associated with worse PROMs at 2 years.

The Femur-First Technique for Oxford Medial Unicompartmental Knee Arthroplasty.

Background: Unicompartmental knee arthroplasty (UKA) is a reliable procedure to treat medial compartment knee osteoarthritis (OA). The reported survivorship of UKA has varied in the literature3-7. In part, the higher failure rates of UKA seen in registries could be related to the caseload and experience of the reporting surgeon8. The introduction of techniques that make procedures more reliable, especially in the hands of inexperienced surgeons, can decrease the rate of failure. With the Oxford UKA implant (Zimmer Biomet), the recommended surgical technique involves cutting the tibia first, followed by the femoral preparation. However, a technique that allows for preparation of the femur first, as well as the use of the femoral component as a reference for the tibial cut, may reduce the common technical errors seen with the procedure. We have utilized the femur-first technique in cases of medial Oxford UKA. Description: The femur-first method outlined in the present article does not require any unique instruments beyond what is supplied by the manufacturer. Before beginning, the femoral positional guide needs to be decoupled from its base. To start, the intramedullary guide is introduced approximately 1 cm anterior and medial to the intercondylar notch. Once the femoral osteophytes are removed, the surgeon identifies the center of the femoral condyle and marks it. The posterior tibial cartilage is then removed with a saw to facilitate the placement of the appropriately sized femoral spherical guide. The size of the femoral component is determined by selecting the implant that aligns best with the width of the femoral condyle. The femoral drill guide is detached from its base because there is not enough space for the base, as the tibia has not yet been resected. The decoupled femoral guide is connected to the intramedullary rod, allowing the precise positioning of the femoral component in approximately 10° of flexion relative to the femoral sagittal plane and drilling of the 2 peg holes. The posterior condylar resection guide is impacted into position, and the osteotomy of the posterior condyle is made. The distal femur is then milled with use of a number-0 spigot, and the femoral component trial is positioned into place. The femoral condyle is "resurfaced" with the femoral component, which restores joint obliquity and the natural height, a critical element of the femur-first technique. Following this, the 1-mm (size-dependent) spherical gauge is placed around the femoral component trial. The tibial guide is secured with the G-clamp and a number-0 resection block, and is pinned into place. We recommend swapping the number-0 cutting guide for a +2 when making the cut in order to avoid over-resection. Recutting is advised if a minimum 3-mm feeler gauge does not adequately occupy the flexion space. The final step is to balance the flexion and extension gaps in the usual fashion. Alternatives: The alternative technique is a traditional tibia-first approach, in which tibial resection is performed prior to femoral resection. As described in the original manufacturer's manual, the tibial cut is accomplished with use of a number-0 cutting guide, and the tibial rotation is based on the axis formed by the anterior superior iliac spine and knee center, irrespective of the femoral condyle. Rationale: The femur-first technique is advantageous in several ways. When performing the femoral cut first, the surgeon can better align the drill guide at the center of medial femoral condyle. This will result in the femoral component being positioned more in line with the coronal plane of the femoral condyle. Additionally, the tibial resection is made with the femoral trial in place; therefore, the depth of resection can be more accurate, potentially avoiding excessive bone resection. Finally, with the femoral trial in place, the surgeon can judge the rotation and medial-lateral position of the tibial component more precisely, hence lowering the possibility of bearing spin-out, impingement, and dislocation or unexplained pain. Expected Outcomes: The femur-first technique is a bone-preserving procedure that results in thinner bearings when compared with a tibia-first approach1. The femur-first approach also improves radiographic outcomes, including femoral coronal, femoral sagittal, and tibial sagittal alignments, while tibial coronal alignment does not differ. There is an early trend toward improved 5-year survivorship with the femur-first (98%) versus tibia-first (94%, p = 0.35) techniques. There has been no significant difference reported in Knee Society Scores between techniques. Important Tips: Perform a preliminary cut of the posterior tibial cartilage in order to allow insertion of the femoral drill guide under the femoral condyle.Make sure the femoral drill guide lies in the center of the marked medial femoral condyle.Align the tibial sagittal cut with the femoral component trial in order to avoid bearing impingement.Be conservative in the tibial cutting by utilizing a +2 cutting guide (since the coupling is performed with the intramedullary guide in place, which drives the tibial guide distally). Acronyms and Abbreviations: UKA = unicompartmental knee arthroplastyFF = femur-firstM-L = medial-lateralAP = anteroposteriorPA = posteroanteriorASA = acetylsalicylic acid (aspirin)BID = bis in die, twice a dayPT = physical therapyTF = tibia-firstFCA = femoral coronal angleFSA = femoral sagittal angleTSA = tibial sagittal angleIM = intramedullaryOA = osteoarthritis.

Impact of unplanned second debridement, antibiotics and implant retention on long-term outcomes in knee exchange arthroplasty: Elevated risk of failure and reinfection.

Purpose: This study investigates the outcomes of two-stage exchange arthroplasty (EA) for periprosthetic joint infection (PJI) following initial or unplanned repeat debridement antibiotics, and implant retention (DAIR). Methods: We retrospectively reviewed cases of knee arthroplasty infection treated with two-stage EA after DAIR, spanning from January 1994 to December 2010. A total of 138 patients were included, comprising 112 with initial DAIR and 26 with an unplanned second DAIR. Data on demographics, comorbidities, infection characteristics and causative organisms were analyzed. The primary outcome was implant failure or reinfection, observed over a minimum follow-up of 10 years. Results: The overall success rate for two-stage EA was 87% (119/138 patients). Factors identified for treatment failure included reinfection with the same pathogen for unplanned second DAIR (hazard ratio [HR] = 3.41; 95% confidence interval [CI] = 1.35-4.38; p = 0.004), higher reinfection rates in patients undergoing EA after an unplanned second DAIR, especially with a prior history of PJI within 2 years (HR = 4.23; 95% CI = 2.39-5.31; p = 0.002), pre-first DAIR C-reactive protein (CRP) levels over 100 mg/dL (HR = 2.52; 95% CI = 1.98-3.42; p = 0.003) and recurrence with the same pathogen (HR = 2.35; 95% CI = 1.32-4.24; p = 0.007). Additional factors such as male gender (HR = 3.92; 95% CI = 1.21-5.25; p = 0.007) and osteoporosis (T score < -2.5; HR = 3.27; 95% CI = 1.23-5.28; p = 0.005) were identified as risk factors for implant failure in all EA cases. Conclusions: This study identifies key risk factors for worse knee EA outcomes following DAIR, including a pre-first DAIR CRP level over 100 mg/L, same pathogen recurrence, and PJI history within 2 years. It shows implant failure rates remain constant across EA cases, regardless of DAIR sequence, particularly with risk factors like male gender and severe osteoporosis (T score < -2.5). These results underscore the need for careful evaluation before an unplanned second DAIR, given its significant impact on EA success. Level of Evidence: Level III.

Influences of Cognitive Function and Depressive Symptoms on Pain Trajectories During the First Year Following Hip Fracture Surgery: A Prospective Cohort Study.

OBJECTIVES: The purposes of this study were to explore trajectories for patterns of postoperative pain intensity during the first year following hip fracture surgery and the relationships between pain trajectory groups, cognitive impairment, and depressive symptoms. DESIGN: A prospective cohort correlational study. SETTING AND PARTICIPANTS: A total of 325 patients aged 60 years or older who had received hip fracture surgery at a 3000-bed medical center in northern Taiwan from September 2012 to March 2020. METHODS: Data were collected before hospital discharge and at 1, 3, 6, and 12 months postdischarge. Pain intensity was measured using a numeric rating scale; cognitive function was measured with the Taiwan version of the Mini-Mental State Examination; and depressive symptoms were measured by the Geriatric Depression Scale-Short Form. Patients with similar postoperative pain trajectories were categorized into groups and compared with group-based trajectory modeling. Cognitive impairment and depressive symptoms associated with each group were identified by logistic regression. RESULTS: Three different pain trajectory groups were identified: drastic decline-minimum pain (47.7%), gentle decline-mild pain (45.5%), and slight decline-moderate pain (6.8%). Patients with cognitive impairment [odds ratio (OR) 11.01, 95% CI 2.99-10.51] and at risk for depression (OR 49.09, 95% CI 10.46-230.30) were more likely to be in the moderate pain group than the minimum pain group. Patients with cognitive impairment (OR 2.07, 95% CI 1.25-3.42) were more likely to be in the mild pain group than the minimum pain group. Patients at risk for depression (OR 9.68, 95% CI 3.16-29.63) were more likely to be in the moderate pain group than the mild pain group. CONCLUSIONS AND IMPLICATIONS: Identifying postoperative pain trajectories can provide insight into the most appropriate pain management for older persons following hip fracture surgery. Attention should focus on assessments for cognitive impairment and risk of depression to prevent persistent postoperative pain. Future studies of older patients with clinically diagnosed cognitive impairment and depression are suggested.