Archives of Orthopaedic and Trauma Surgery最新文献

Introduction

Stress shielding and altered load transfer remain major concerns in total hip arthroplasty (THA). Stem fixation method and material properties strongly influence femoral stress distribution, but data directly comparing cementless and cemented stems of identical geometry are limited.

Materials and methods

Six fourth-generation composite femurs were used. Three were implanted with a fully hydroxyapatite-coated cementless stem, and three with a polished cemented stem. Mechanical loading of 100–1900 N at 5 Hz was applied to simulate single-leg stance. Thermoelastic stress analysis (TSA) was used to evaluate surface stress distribution across Gruen zones. Linear mixed models assessed differences between groups.

Results

Before implantation, the highest stress was observed in the proximal femur. After implantation, stress shifted distally in both fixation methods. The cementless stem maintained higher compressive stress in the proximal-medial region compared with the cemented stem, which demonstrated a more uniform stress distribution between the medial and lateral cortices. TSA measurements confirmed significant proximal stress reduction with cemented fixation, while cementless fixation preserved proximal loading more effectively.

Conclusion

This simulation study showed that fixation method and material influence short-term femoral stress distribution, even when stem geometry is identical. These findings describe only mechanical behavior under simplified conditions. The use of composite femurs, the one-size difference between stems, and the short-term evaluation limit the generalizability of the results. Further research using cadaveric models and clinical follow-up is required to clarify long-term remodeling and support stem selection in total hip arthroplasty.

Introduction

Evidence on the outcome of aseptic exchange of rotating-hinge prosthesis is missing in the literature. This study aimed to evaluate implant survival, complication rates, and clinical outcomes following revision of a rotating-hinge prosthesis to another rotating-hinge prosthesis with anatomical axis.

Materials and methods

Between March 2014 and Juli 2023 62 cases of aseptic exchange of a rotating-hinge prosthesis were performed at a tertiary medical center in Germany. In this retrospective study, all patients were contacted for clinical follow-up and prosthesis survival. Implant survival was analyzed using the Kaplan-Meier method, and clinical outcomes were assessed using the Knee Society Score.

Results

The 5-year implant survival rate was 83.4% (73.2–93.6, 95%-CI) for revision due to any reason, 85.1% (75.3–94.9, 95%-CI) for aseptic failure and 98.0% (94.1–100.0, 95%-CI: ) for septic failure. The estimated 10-year survival rates were 73.2% (59.2–87.1%; 95%-CI), 78.0% (65.1–90.9%; 95%-CI), and 93.9% (85.3–100.0%; 95%-CI), respectively. Improvements were observed in all KSS subdomains except for the Patient Expectation Score.

Conclusions

The exchange of a rotating-hinge prosthesis, using metaphyseal cones when indicated for bone defects, yields implant survival and complication rates comparable to those of primary rotating-hinge prosthesis implantation. However, clinical outcome scores tend to be lower than those reported for first-time implantation of rotating-hinge prostheses.

Background

The aim of this systematic review is to compare the short-term clinical outcomes between early (EDF) and late definitive fixation (LDF) in polytraumatized patients with pelvic ring fractures (PRF).

Method

In accordance with PRISMA guidelines, a comprehensive search using Boolean operators was performed in June 2022 from the following databases: Embase, Medline and Cochrane Library. Studies comparing EDF and LDF for PRF in polytrauma patients defined as ISS > 15 were included. All included cohorts performed definitive fixation after haemodynamic stabilisation or adequate response to resuscitation. Random effects meta-analyses of pooled raw data were employed using the Mantel-Haenszel and Inverse -variance methods. The methodological quality of studies was assessed using the Newcastle Ottawa Scale.

Results

Out of 869 studies screened, 10 were included in the meta-analysis with a total of 2918 patients. All included studies were retrospective; no randomized trials were identified. The most common time point used by 7 studies to define EDF was within 24 h of hospital admission and LDF (> 24 h). The most common reasons for LDF were surgeon’s choice, availability of pelvic surgeon and transfer from other hospitals. Our meta-analysis revealed that EDF was associated with a reduced length of hospital stay (WMD=-3.52 days; 95% CI: [-5.43 to -1.62], p < 0.0003) and lower incidence of ARDS (RR = 0.50; 95% CI: [0.26 to 0.96], p = 0.04). No significant association was found in mortality, length of ICU stay, multi-organ failure, sepsis and surgical site infection between EDF and LDF.

Conclusion

These findings suggest that early definitive fixation may be a safe and viable option with no increased risk of complications and mortality. However, the adequacy of resuscitation and the estimate of physiologic reserve should be balanced with the risks of operative fixation in all patients. Further prospective validation studies are warranted to test the predictive ability of the various proposed trauma care models and stratify patients for EDF.

Introduction

The widely accepted indications for unicompartmental knee arthroplasty (UKA) emphasize bone-on-bone contact, and early osteoarthritis (OA) of Kellgren–Lawrence (KL) grade ≤ 2 is considered a contraindication. The present study aimed to clarify the differences in clinical outcomes of UKA between patients with early OA (KL ≤ 2) and those with advanced OA (KL ≥ 3), the latter representing the conventional indication for this procedure.

Materials and Methods

Eighty-four UKA patients with ≥ 1 year follow-up were retrospectively divided into early OA (KL ≤ 2; n = 32) and advanced OA (KL ≥ 3; n = 52) groups. Preoperative magnetic resonance imaging (MRI) was used to examine meniscal and cartilage lesions. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analog scale pain score, both preoperatively and at the final evaluation. Patient characteristics, clinical scores, and changes in clinical scores were compared between the early OA (KL ≤ 2) and advanced OA (KL ≥ 3) groups.

Results

The early OA (KL ≤ 2) group (n = 32) had a mean age of 70.5 years with 35.3 months’ follow-up, while the advanced OA (KL ≥ 3) group (n = 52) had 70.0 years with 31.6 months (both 12–60 months). The early OA (KL ≤ 2) group showed a high incidence of medial meniscus posterior root tears (MMPRT; 75.0%) and subchondral insufficiency fractures (SIFK; 56.3%). After false discovery rate (FDR) adjustment, preoperative and postoperative clinical scores did not differ significantly between groups. However, the change in KOOS-sports and recreation function (Sport/Rec) was significantly higher in the early OA (KL ≤ 2) group compared with the advanced OA (KL ≥ 3) group (P = 0.020 after FDR adjustment). The effect sizes were 0.55 for KOOS-Sport/Rec.

Conclusions

UKA may be considered for carefully selected patients with MRI-confirmed medial compartment lesions and early OA (KL ≤ 2), but these results should be interpreted cautiously pending long-term, multicenter validation.

Introduction

Medial unicompartmental knee arthroplasty (UKA) has become an established alternative to total knee arthroplasty (TKA) for isolated medial compartment osteoarthritis, offering faster recovery and better functional outcomes. However, results during the early phase of institutional adoption may vary depending on surgeon experience and procedural standardization. This study aimed to evaluate early clinical outcomes, complication rates, revision profiles, and the learning curve associated with the initial institutional adoption of medial mobile-bearing UKA in a high-volume, multi-surgeon center.

Methods

This prospective case series included 154 consecutive medial UKAs performed by five surgeons on 152 patients. Pre- and postoperative KOOS and NPRS were recorded up to a 24-month follow-up, with a 100% follow-up rate. The primary endpoint was improvement in pain and function as measured by NPRS and KOOS. Inclusion/exclusion criteria, surgical technique, and rehab protocol were standardized.

Results

Mean NPRS improved significantly from 7.6 ± 1.4 preoperatively to 1.8 ± 1.9 at 24 months (p < 0.001). Total KOOS increased from 31.0 ± 12.5 to 88.0 ± 13.4 (p < 0.001), with all subscales exceeding the minimal clinically important difference. The two-year revision-free survival rate was 94.8% (95% CI 90.5–97.0%). A total of 9 complications (5.8%) occurred, mostly early technical events related to the initial learning curve, including three bearing dislocations.

Conclusion

Medial UKA showed excellent early outcomes with a low revision rate and a complication profile consistent with the expected early technical learning phase. These findings support the safe and effective institutional introduction of medial UKA, emphasizing the importance of structured training and standardized protocols for successful early adoption.

The management of increased posterior tibial slope (PTS) in anterior cruciate ligament (ACL) injuries and insufficiencies and especially the indication for slope changing osteotomies has evolved to a highly discussed topic. The majority of available studies refer to cut-off values for the PTS and the number of previous ACL reconstructions in their indications. However, ACL injuries are a complex multifactorial problem, and available recommendations mainly ignore these highly individual factors, in their presence, and also in their complexity. Actually, many of the known risk factors for ACL insufficiency are also directly or indirectly associated with PTS. Therefore, the purpose of this paper is to propose a whole new way of thinking about complex ACL treatment strategies by integrating the PTS in a comprehensive approach of individual risk assessment and decision making. It is inspired by an established risk stratification system in a completely different but also very comparable field: avalanches. It is ultimately based on the thorough analysis of individual risk factors and accompanying circumstances on the one hand, and the standardized measured PTS on the other hand. These then define a point on a heat map (in a coordinate system) which, through the underlying colour, reflects the strength of the recommendation for a slope correction. This is to introduce The Avalanche Concept.

Introduction

This study aimed to radiographically compare cephalomedullary nails (CMN) and compression hip screws (CHS) in stable intertrochanteric femoral fractures, specifically assessing femoral offset (FO), neck-shaft angle (NSA), and leg length discrepancy (LLD).

Materials and methods

This study retrospectively reviewed 181 patients treated between October 2020 and March 2024. After exclusions, 59 patients (CHS: 32; CMN: 27) with AO/OTA 31A1 fractures were included. Radiographic parameters (NSA, FO, and LLD) were measured using pre- and postoperative radiographs and preoperative CT. Rotational and magnification corrections were applied. Group comparisons were conducted using the Mann–Whitney U and Fisher’s exact tests.

Results

Postoperative and final NSA were significantly smaller (more varus) in the CMN group compared with the CHS group (postoperative NSA: 125.4° ± 8.0° vs. 133.0° ± 8.4°, p < 0.001). Measured FO was greater in the CMN group postoperatively and at final follow-up, but differences were not significant after correction. LLD was significantly greater in the CMN group (corrected postoperative LLD: CMN − 3.6 ± 3.5 mm vs. CHS 1.1 ± 2.5 mm, p < 0.001). Corrected NSA and FO did not differ significantly from those on the contralateral side in either group, and the proportion of patients with > 20% FO deviation was comparable. Bone union occurred in 58 of 59 cases; one CMN case required reoperation due to cut-through. Functional Ambulation Category scores showed no significant differences.

Conclusion

CHS tended toward valgus and CMN tended toward varus alignment; however, corrected NSA and FO were restored to near-contralateral values in both groups. Limb shortening was greater after CMN fixation, although it was likely not clinically significant. Both implants provided reliable fixation and similar functional outcomes. Larger studies assessing detailed gait parameters are warranted to clarify the clinical impact of these radiographic differences.

Background

Periprosthetic joint infection (PJI) is a serious complication of total joint arthroplasty (TJA). Early diagnosis is challenging, but blood cell ratios offer a cost-effective and accessible tool. This study aimed to evaluate the diagnostic accuracy of the monocyte-to-lymphocyte ratio (MLR) for PJI diagnosis

Methods

A systematic review and meta-analysis were conducted using MEDLINE, Scopus, Embase, Web of Science, and Cochrane Central up to September 2024. Cross-sectional studies comparing the diagnostic accuracy of MLR to a standard reference for PJI diagnosis were included. Pooled sensitivity, specificity, likelihood ratios (LR), DOR, and summary receiver operating characteristic (SROC) curve were calculated. Quality was assessed using QUADAS-2 tool.

Results

Nine studies with 3,026 participants met the inclusion criteria. The pooled sensitivity and specificity of MLR were 73% (95% CI, 66%−79%; I² = 86.2%) and 70% (95% CI, 61%−78%; I² = 89.9%), respectively. The pooled DOR was 6.51 (95% CI, 4.29−9.88; I² = 80.6%), and the AUC was 0.794. For an MLR cut-off of 0.4, sensitivity was 73% (95% CI, 66%−79%; I² = 80.1%), specificity was 78% (95% CI, 72%−82%; I² = 80.4%), LR+ was 3.21 (95% CI, 2.3−4.4; I² = 50.9%), LR− was 0.34 (95% CI, 0.24−0.49; I² = 56.7%), and DOR was 9.59 (95% CI, 5.3−17.2; I² = 87.4%)

Conclusion

The MLR demonstrates moderate diagnostic accuracy for PJI, highlighting its potential as a cost-effective and accessible biomarker. Given the substantial heterogeneity, the current evidence suggests that MLR could serve as a supplementary tool within a broader diagnostic panel, rather than a standalone test. Future research should focus on standardizing cut-off values and validating its clinical application in diverse patient populations.

Introduction

Kienböck’s disease is a progressive avascular necrosis of the lunate that causes wrist pain and functional impairment. Surgical intervention is often needed for advanced stage IIIB disease to relieve symptoms and preserve the carpal structure. Scaphocapitate (SC) arthrodesis is an established technique, but the value of lunate excision versus preservation remains debated. This study prospectively compared the outcomes of SC arthrodesis performed with and without lunate excision.

Materials and methods

This prospective comparative study included 38 patients with stage IIIB Kienböck’s disease, who were allocated to receive SC arthrodesis with lunate preservation (n = 19) or lunate excision (n = 19). The follow-up time was 84 months. The primary outcome measure was pain intensity, which was assessed via the visual analogue scale (VAS) for pain. The secondary outcomes included wrist function evaluated by the modified Mayo wrist score (MMWS) and patient-rated wrist evaluation (PRWE), grip strength, wrist range of motion (ROM), and radiographic parameters such as ulnar variance, the carpal height ratio (CHR), the carpal ulnar distance (CUD), and the radioscaphoid (RS) angle. The union rate, time to union, time to return to work, and incidence of postoperative complications were also recorded.

Results

Both groups demonstrated significant postoperative improvement in pain (VAS pain score, p = 0.001). At 84 months, the preservation group achieved superior pain control, with a lower mean VAS score (5 versus 12, p = 0.001). The preservation group also maintained a greater CUD (30 mm versus 23 mm, p = 0.001) and exhibited later onset of degenerative changes. MMWS improved from 49 to 73 in the preservation group and from 48 to 72 in the excision group. The PRWE scores decreased from 69 to 21 in the preservation group and from 67 to 24 in the excision group. The final grip strength reached 88% of that of the contralateral side in the preservation group and 84% in the excision group, with no significant difference in ROM. The union rates were 93% for preservation and 91% for excision. The excision group presented higher rates of degenerative changes (16 versus 8 cases) and nonunion (2 versus 1). No major differences were found in the infection rate, sympathetic reflex dystrophy, or return to work.

Conclusions

SC arthrodesis provides reliable long-term pain relief in patients with stage IIIB Kienböck’s disease. Lunate preservation provides superior pain control and carpal alignment, reduces degenerative sequelae, and is recommended where feasible.

Background

Dislocation of a total hip arthroplasty (THA) is a highly disabling complication following the implantation of primary and revision hip arthroplasties, as well as a prevalent reason for subsequent revisions. This study is designed to evaluate the survival rate, functional outcomes, and the reasons for further revision due to implant failure of Constrained Acetabular Liners (CALs).

Methods

56 patients underwent hip revision surgery using a Constrained Acetabular Liner between June 2018 and December 2022 were retrospectively evaluated. Inclusion criteria consisted of age > 18 years, follow-up of at least 12 months, prior total hip arthroplasty or bipolar hemiarthroplasty, a history of recurrent implant dislocation, or, alternatively, the presence of a high risk of implant instability in hip revisions due to mechanical conditions.

Results

The average age at the time of surgery was 72.4 years (SD 12.4). 55.6% of implants were performed for recurrent dislocation of THA, 8.9% for recurrent dislocation of bipolar hemiarthroplasty, 13.3% for aseptic loosening revisions, 4.4% for adverse reactions to metal debris revision procedures, and 17.8% for two-stage revision for periprosthetic joint infection. The average follow-up at the final evaluation was 32 months (SD 12.3). The survivorship of the implant was 88.9% at final follow-up. At the final follow-up: average HHS 77.4 ± 13.2; average WOMAC 31.4 ± 13.4; average OHS 32.1 ± 6.9; and average FJS-12 69.5 ± 19.6., and 65% showed excellent or good outcomes (HHS > 80).

Conclusions

The CALs assessed in this study have shown satisfactory functional outcomes, even when compared with other anti-dislocation systems available on the market. Both cemented and uncemented solutions have shown a good survival rate in the mid-term. However, their use should be reserved for selected cases.