Guarin Perez, Sergio F

Aims Extensor mechanism disruption is a major complication following total knee arthroplasty, with treatment often consisting of extensor mechanism reconstruction utilizing monofilament polypropylene mesh (Marlex mesh, C. R. Bard, Inc). Infection following this procedure is devastating, often resulting in revision surgery and mesh removal, with permanent limb dysfunction. This study evaluated the in vitro ability of vancomycin-loaded polypropylene mesh to inhibit growth of isolates of three Staphylococcus species from patients with periprosthetic joint infection. Methods The mesh was prepared in two configurations – single-layer and eight-layer – and soaked for ten minutes in either sterile water (control) or vancomycin solution (50 mg/ml), after which the mesh was placed on tryptic soy agar plates inoculated with staphylococci and incubated at 37°C for 18 to 24 hours. Zones of inhibition were measured daily over seven days, with mesh transferred to freshly inoculated plates daily. Testing was performed in triplicate, with experiments repeated three times for each bacterial isolate. A total of 30 clinical isolates were tested (five methicillin-susceptible Staphylococcus epidermidis , five methicillin-resistant S. epidermidis , ten methicillin-resistant Staphylococcus aureus , and ten Staphylococcus lugdunensis ). Results Across all species, the eight-layer vancomycin-loaded mesh produced statistically significantly larger median zones of inhibition than the single-layer mesh. The antibacterial activity of the eight-layer mesh persisted through to day 7, while the single-layer mesh showed reduced activity by days 4 to 5. Conclusion Compared with single-layer vancomycin-loaded mesh, multilayer vancomycin-loaded mesh, which mimics clinical application, provides enhanced and sustained antibacterial activity in vitro. Cite this article: Bone Joint Res 2026;15(8):998–1004.

Background: Prior studies have reported higher rates of periprosthetic fracture, superficial infection, and neurologic deficit with the direct anterior approach (DAA), and higher rates of dislocation with the posterior approach (PA) for total hip arthroplasty (THA). Despite these differences, the overall clinical burden of complications between approaches remains unclear. The purpose of this study was to compare the profiles, severity, impact, and resolution of 5 clinically important complications between DAA and PA THA. Methods: A retrospective review was conducted of 11,783 consecutive primary THAs performed between 2010 and 2021 across 3 centers within a single healthcare system, using either the DAA (n = 4,451) or the PA (n = 7,332). Complications assessed included dislocation, infection, periprosthetic fracture (PPFx), aseptic loosening, and neurologic deficit. Severity was graded using the Clavien-Dindo classification (I = minor, V = death). Impact was defined by reoperation burden, and outcomes were categorized as resolved or persistent. Kaplan-Meier survivorship and propensity-weighted Cox proportional hazards models were used to compare complication risk. Results: The overall 1-year risk of surgical complications did not differ between DAA and PA (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.75-1.06; p = 0.208). Dislocation occurred more frequently with PA THA than DAA THA (1.9% vs. 0.4%; HR, 5.20; 95% CI, 3.04-8.90; p < 0.001). Superficial infections were more frequent with the DAA (1.6% vs. 0.8%; HR, 2.43; 95% CI, 1.68-3.53; p < 0.001). The risk of deep infection, PPFx, aseptic loosening, and neurologic deficit did not differ significantly between approaches. Among patients with complications, the proportion classified as severe (Clavien-Dindo III–V) was similar, and adjusted analyses showed no difference in the odds of severe complications (adjusted odds ratio 1.34 for PA vs DAA; 95% CI, 0.95-1.91; p = 0.099). Complication impact and resolution were likewise comparable. Conclusion: Although the profile of complications differed between DAA and PA THA, the severity, early clinical impact, and resolution of complications appeared similar. Notably, DAA was associated with a lower risk of dislocation and a higher risk of superficial infection compared with PA THA. Level of Evidence: Level III , Retrospective Comparative Study. See Instructions for Authors for a complete description of levels of evidence.

Background: Greater trochanteric (GT) fractures after total hip arthroplasty (THA) are typically managed nonoperatively. However, outcome data for patient counseling remain limited. We evaluated the nonoperative results, focusing on fracture union rates and the presence of persistent limp in relation with fracture location, displacement magnitude, and direction. Methods: We retrospectively reviewed 82 postoperative GT fractures not associated with trochanteric osteolysis following primary THA performed between 1984 and 2020. The mean follow-up was 9 years. Fracture location was classified relative to the contralateral lesser trochanter as tip, waist, or base. Initial displacement, migration, final displacement, and bony union were assessed radiographically. Clinical outcomes included the presence of a persistent limp and Harris Hip Score. Multivariable analyses were performed to identify factors associated with nonunion and limp. Results: Fractures were classified as tip (n = 32), waist (n = 29), or base (n = 21). The mean initial displacement was 8.9 mm, with 43% displaced >10 mm. Initial displacement was significantly lower in base fractures (4.8 mm) compared with tip (10.1 mm) or waist (10.8 mm) fractures (p < 0.05). The mean final displacement was 14.6 mm. 45% of fractures achieved complete bony union, and 38% of patients demonstrated a persistent limp. In multivariable analysis, greater final displacement (>12 mm), and tip and waist fractures were independently associated with nonunion. Posterior fracture displacement was significantly associated with persistent limp. Conclusions: Outcomes following nonoperative management of GT fractures after THA depend on fracture morphology and displacement characteristics. Tip and waist fractures and fractures with final displacement >12 mm have a higher risk of nonunion, whereas posterior and superior displacement is associated with persistent limp. Greater than 20 mm of displacement is associated with both limp and nonunion. These findings may assist surgeons in counseling patients and in identifying fracture patterns at higher risk for adverse outcomes of nonoperative management. Level of Evidence: Level III (Prognostic Study). See Instructions for Authors for a complete description of levels of evidence.

Background/Objectives: Diagnostic evaluation and management of nontraumatic osteonecrosis of the femoral head (ONFH) vary substantially. This systematic review was conducted to inform development of the Association Research Circulation Osseous (ARCO) clinical practice guideline for diagnosis and treatment of ARCO stages I to III ONFH. Methods: We searched MEDLINE, EMBASE, Web of Science, SCOPUS, Global Index Medicus, and the Cochrane Library for studies evaluating imaging modalities and treatments for adult ONFH. We assessed risk of bias using the QUADAS-2, the ROB-2, and the ROBINS-I tools; conducted meta-analyses using random-effects regression; and evaluated certainty of evidence using GRADE methodology. Results: Among 36 included studies, 18 addressed diagnostic test accuracy and 18 addressed comparative effectiveness of treatments. Magnetic resonance imaging (MRI) demonstrated the highest pooled sensitivity (0.91; 95% confidence interval (CI), 0.87 to 0.94) and specificity (0.96; 95% CI, 0.87 to 0.99) for ONFH diagnosis. Bone marrow edema and grade 2+ joint effusion on MRI differentiated symptomatic versus asymptomatic disease. Computed tomography and MRI better detected subchondral fractures than plain radiography. Very low-grade evidence suggested lower rates of femoral head collapse with core decompression plus bone marrow concentrate compared with core decompression alone (pooled relative risk [RR], 0.55; 95% CI, 0.36 to 0.83), and with vascularized versus non-vascularized bone grafting (RR, 0.35; 95% CI, 0.14 to 0.84) over a ≤5-year follow-up. Based on three non-comparative case series, osteotomies might have a lower risk of collapse over a 10- to 20-year follow-up, but this needs to be evaluated in future comparative research. Inconsistent outcome reporting hindered treatment outcome pooling. There were no comparative studies that evaluated observation only versus intervention in asymptomatic disease or strategies for monitoring treatment response. Conclusions: Evidence supporting optimal imaging modalities and early joint-preserving interventions remains limited and predominantly observational, underscoring the need for high-quality comparative studies with consistently defined core outcomes to guide clinical decision-making.

Aims Heterotopic ossification (HO) is a recognized complication following periacetabular osteotomy (PAO), but its patterns, incidence, and clinical relevance remain poorly defined. The commonly used Brooker classification, developed for total hip arthroplasty, is not fully applicable to HO after PAO. This study aimed to propose a new classification system specific to HO after PAO, evaluate its clinical relevance, and report the cumulative probabilities of radiological and symptomatic HO. Methods This retrospective study included 643 patients who underwent PAO between January 2006 and July 2024. A total of 308 patients (47.9%) had concomitant arthroscopic procedures. Radiographs were analyzed to identify HO using both the Brooker classification and a newly developed system. The cumulative probabilities of radiological and symptomatic HO were calculated using Kaplan-Meier analysis. Difference of variables between patients with and without HO was analyzed. Receiver operating characteristic (ROC) curve analysis was used to compare the predictive performance of the two classification systems. Results The cumulative probabilities of radiological and symptomatic HO at five years post-PAO were 30.4% and 3.8%, respectively. The probabilities were 41.9% in males and 29.2% in females. Four patients (2.8%) required surgical excision of HO, all classified as type 3 or 4 under the new system. The ROC analysis demonstrated superior predictive performance for the new classification system (AUC = 0.928) compared to the Brooker classification (AUC = 0.697; p = 0.007). No significant differences were found between the patients with and without HO in terms of age, sex, concomitant arthroscopic procedures, or receiving prophylaxis in addition to low-dose aspirin. Conclusion This study highlighted the cumulative probabilities of HO following PAO and introduced a new classification system that improved clinical relevance and predictive accuracy. These findings have provided insights into the incidence and management of HO after PAO, and laid the groundwork for standardized reporting and future research. Cite this article: Bone Jt Open 2025;6(11):1436–1445.

Background: Hip decompression effectively treats early-stage osteonecrosis of the femoral head (ONFH) by slowing disease progression and potentially delaying joint replacement. Biological adjuvants like bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) support bone regeneration and improve outcomes 1–7 . The present video article demonstrates a simple, coreless hip decompression technique with BMAC and PRP injection for early-stage ONFH. Description: The procedure is performed in the same operating room setting as traditional core decompression, with the patient supine on a radiolucent table for fluoroscopic guidance. One or both legs are draped free for access to the iliac crests. Bone marrow is harvested percutaneously from the anterior superior iliac crest with a trocar needle kit, centrifuged, and prepared for injection. We recommend precoating needles and syringes with 1:1,000 heparin to prevent clotting. The BioCUE System (Zimmer Biomet) is typically utilized for centrifugation. Hip decompression is performed with use of a trocar and cannula (PerFuse System; Zimmer Biomet), with subsequent injection through the cannula into the femoral head. A 0.5-cm skin incision is made. The trocar is placed lateral to the femur and advanced percutaneously through the lateral femoral cortex, with a starting point proximal to the lesser trochanter. The trocar is then advanced along the femoral neck into the necrotic region by performing mallet strikes on the instrument’s strike cap. Anteroposterior and frog-leg lateral views assist in positioning the trocar within the necrotic area. Internal leg rotation, which aligns the patella upward, helps position the trocar horizontally parallel to the floor. Positioning is adjusted using repeated imaging as needed. Once the patient is positioned, the trocar is removed, leaving the cannula in place. With the cannula retracted 1 cm, a 30-mL syringe is utilized to inject BMAC and PRP into the necrotic lesion. Because of sclerotic resistance, substantial pressure is needed, but retraction of the cannula helps. Following injection, the cannula is withdrawn another 1 cm, and demineralized bone matrix is injected to prevent escape of the BMAC. Alternatives: Alternative treatments for ONFH include traditional core decompression with a sliding hip screw drill or an X-REAM device (Stryker), both of which carry a higher risk of fracture because of the larger diameter of the tract and require limited weightbearing postoperatively. Bone-cement injection can stabilize the femoral head but lacks regenerative properties. Core decompression with either BMAC or PRP alone, rather than in combination, also serves as an alternative treatment strategy. Open approaches, like osteotomy, are more invasive, have longer recovery times, and may complicate future hip arthroplasty if unsuccessful. Rationale: This technique enables minimally invasive hip decompression and delivery of adjuvant cell therapy or grafting, typically without the use of power instruments. This approach avoids the risk of injuring the bone due to the heat from power tools, protecting the BMAC injection site. Patients are generally discharged the same day and permitted full weight-bearing immediately, even in bilateral surgeries. Expected Outcomes: Hip decompression for ONFH has shown variable rates of success 8,9 , but adding BMAC or PRP may improve outcomes 1–3 . Houdek et al. reported that among 35 hips treated with decompression plus BMAC and PRP for corticosteroid-induced ONFH, 88% avoided THA at 3 years 2 and 70%, at 7 years 3 . Patients with grade-1 or 2 Kerboul angles had a 90% survivorship rate, underscoring the benefits of BMAC and PRP. Important Tips: Insert the trocar into the lateral cortex, positioned distal to the vastus ridge and proximal to the lesser trochanter, to reduce iatrogenic subtrochanteric fracture risk. Avoid advancing closer than 5 mm to the subchondral cortex to prevent joint-surface disruption or collapse, especially with eccentric lesions. If resistance occurs during injection, retract the cannula a few millimeters laterally to increase delivery space and reduce pressure. Acronyms and Abbreviations: BMAC = bone marrow aspirate concentrate ONFH = osteonecrosis of the femoral head PRP = platelet-rich plasma AP = anteroposterior THA = total hip arthroplasty ARCO = Association Research Circulation Osseous classification MRI = magnetic resonance imaging

Abstract The Guardian table is widely utilized for combined hip arthroscopy and periacetabular osteotomy (PAO) due to its postless traction design and the ability to perform both procedures without the need for redraping. This retrospective cohort study reports one surgeon’s use of the Guardian table extension during combined hip arthroscopy and PAO and the occurrence of intraoperative posterior column fractures. Seventy-two consecutive PAO procedures performed at a single institution between February 2023 and January 2025 were analysed. Procedures involving concomitant hip arthroscopy (n = 26) utilized the Guardian table, whereas those without arthroscopy (n = 46) used a conventional radiolucent table. Patient demographics, clinical data, and complications were reviewed. Additionally, mechanical testing quantified table stability by measuring peak absolute acceleration (‘table bounce’) using accelerometry during simulated malleting. The incidence of intraoperative posterior column fractures was significantly higher with the Guardian table (4/26, 15.4%) compared to the conventional table (0/46, 0%; P = .0062). Mechanical testing demonstrated significantly greater table bounce for the Guardian table (69.1 ± 3.4 m/s2 versus 28.2 ± 4.4 m/s2, P &lt; .001). Patient characteristics and surgical complexity did not differ significantly between fracture and non-fracture cases. These findings suggested that the Guardian table extension system was associated with increased risk of posterior column fractures, likely due to lack of distal support and stability. Surgeons should consider alternative table setups or intraoperative support modifications to mitigate this risk during PAO procedures.

AimsPeriacetabular osteotomy (PAO) is a complex procedure for treating hip dysplasia by reorienting the acetabulum to slow osteoarthritis progression. This study aimed to assess the types and rates of complications after PAO and provide recommendations for prevention.MethodsA total of 715 consecutive patients underwent unilateral PAO by a single surgeon between December 2006 and January 2024, with at least one year of follow-up. Indications included hip dysplasia, acetabular retroversion, and protrusio. Hip arthroscopy was performed concurrently in 325 cases. Demographic factors, perioperative data, and complications – graded using the modified Clavien-Dindo system – were analyzed. Risk factors and learning curves were also assessed.ResultsOf the 715 patients, 121 (16.6%) experienced 144 complications. There were 68 grade I, 52 grade II, 23 grade III, one grade IV, and 0 grade V complications. The 23 grade III complications requiring reoperations included four revision PAOs for overcorrection, three fixations for posterior column fracture, four neurolysis procedures for symptomatic lateral femoral cutaneous nerve (LFCN) dysesthesias, four heterotopic bone excisions, and eight wound debridements. All type I and II complications were treated without sequelae. The addition of hip arthroscopy did not increase complication rates. Age < 20 years was associated with a lower risk of complications (odds ratio (OR) = 0.53, 95% CI 0.33 to 0.84, p = 0.008), whereas smoking history (OR = 1.72, 95% CI 1.01 to 2.87, p = 0.040) and correction of both acetabular dysplasia and retroversion (OR = 2.46, 95% CI 1.08 to 5.24, p = 0.024) were linked to an increased risk of complications. The operating time and incidence of complications decreased with increasing experience.ConclusionPAO is an effective procedure with an acceptable complication rate. Risk factors should be discussed during preoperative counselling. While patient optimization may help to reduce complications, precise intraoperative technique remains critical for minimizing risk.Cite this article: Bone Jt Open 2025;6(10):2022–2031.

Background: An extended trochanteric osteotomy (ETO) is commonly used to improve exposure and facilitate femoral component removal in revision total hip arthroplasty (THA). An additional medial corticotomy may be used in conjunction with an ETO to correct a femoral deformity, particularly varus remodeling in association with a failed femoral component. This study evaluated the outcomes of combining an ETO with a medial corticotomy in revision THA, with emphasis on implant fixation, femoral alignment, bone union, and clinical outcomes. Methods: Of the 612 ETOs performed between 2003 and 2013, 13 patients (9 men and 4 women) underwent ETO combined with a medial corticotomy to correct varus remodeling, representing 2% of all ETOs during that period. The average follow-up was 8 ± 3.5 years. The mean age at surgery was 67 ± 13.5 years. The mean body mass index was 32 ± 7.7 kg/m 2 . Radiographs were reviewed to measure preoperative and postoperative femoral deformity, time to consolidation, and femoral fixation. Clinical outcomes were evaluated using the Harris Hip Score (HHS). Results: All patients had preoperative varus femoral deformity (mean 16.3° ± 5.7°). The mean postoperative alignment was 4.3 ± 1.6° varus achieving an average correction of 12° (95% CI −15.7 to −8.3, p < 0.0001). Both the ETO and the medial corticotomy consolidated in 10 of 11 patients (91%) with available 1-year radiographs at a mean of 11 ± 7.7 months. The mean HHS improved significantly from 42 preoperatively to 82 at 5-year follow-up (p = 0.0002). Complications related to the ETO and corticotomy occurred in 4 patients (30%), including 1 intraoperative fracture, 1 postoperative greater trochanteric fracture, 1 nonunion of the medial corticotomy, and 1 postoperative wound-hematoma. All femoral components remained well fixed at final follow-up. Conclusion: The combination of ETO and medial corticotomy in revision THA effectively corrected femoral alignment in patients with a preoperative varus deformity and was associated with significant functional improvement at the final follow-up. Level of Evidence: Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Gluteus medius tears and atrophy cause lateral hip pain, limp, and functional impairment. We developed the “broken wing sign,” a novel physical examination test for detecting gluteus medius tendon tears and muscle degeneration. This study evaluated its diagnostic accuracy and clinical utility against magnetic resonance imaging (MRI) and intraoperative findings. Methods: We prospectively examined 59 patients (75 hips; mean age, 69.5 ± 10.8 years; 48 women) with suspected hip abductor insufficiency. The broken wing sign was tested with patients prone, the knee flexed at 90°, and the hip actively extended. A positive sign involved ≥10° of compensatory external hip rotation, visible as an inward drift of the foot, indicating gluteus medius (and resulting internal rotation) weakness. MRI served as the reference standard for classifying gluteus medius integrity as no tear, partial, full-thickness, or massive. Fatty infiltration was graded (Goutallier grades 0 to 4), quantified, and analyzed for a correlation with the examination findings. Diagnostic accuracy metrics were calculated. Results: The broken wing sign demonstrated high accuracy (sensitivity, 81.8%; specificity, 80.0%; positive predictive value [PPV], 91.8%; negative predictive value, 61.5%; diagnostic odds ratio, 17.8). An external rotation threshold of ≥30° yielded 100% specificity and 100% PPV for a tear. The sign detected acute tears with no or minimal fatty infiltration (100% sensitivity for massive tears). The degree of the external rotation angle was strongly correlated with muscle atrophy with fatty infiltration, showing 88.0% sensitivity for Goutallier grade ≥3 and 100% sensitivity for grade 4. Conclusions: The broken wing sign is clinically useful for diagnosing gluteus medius tendon tears and muscle atrophy, particularly massive tears and advanced fatty degeneration. It effectively guides MRI utilization and surgical planning, serving as a valuable initial diagnostic tool in the clinical setting. Level of Evidence: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.