Aims

Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) have both been shown to be effective treatments for osteoarthritis (OA) of the knee. Many studies have compared the outcomes of the two treatments, but less so with the use of robotics, or individualized TKA alignment techniques. Functional alignment (FA) is a novel technique for performing a TKA and shares many principles with UKA. Our aim was to compare outcomes from a case-matched series of robotic-assisted UKAs and robotic-assisted TKAs performed using FA.

Aims

Limb salvage surgery (LSS) is the primary treatment option for primary bone malignancy. It involves the removal of bone and tissue, followed by reconstruction with endoprosthetic replacements (EPRs) to prevent amputation. Trabecular metal (TM) collars have been developed to encourage bone ingrowth (osseointegration (OI)) into EPRs. The primary aim of this study was to assess whether OI occurs when TM collars are used in EPRs for tumour.

Aims

Functional alignment (FA) in total knee arthroplasty (TKA) aims to achieve balanced gaps by adjusting implant positioning while minimizing changes to constitutional joint line obliquity (JLO). Although FA uses kinematic alignment (KA) as a starting point, the final implant positions can vary significantly between these two approaches. This study used the Coronal Plane Alignment of the Knee (CPAK) classification to compare differences between KA and final FA positions.

Aims. The transepicondylar axis is a well-established reference for the determination of femoral component rotation in total knee arthroplasty (TKA). However, when severe bone loss is present in the femoral condyles, rotational alignment can be more complicated. There is a lack of validated landmarks in the supracondylar region of the distal femur. Therefore, the aim of this study was to analyze the correlation between the surgical transepicondylar axis (sTEA) and the suggested dorsal cortex line (DCL) in the coronal plane and the inter- and intraobserver reliability of its CT scan measurement. Methods. A total of 75 randomly selected CT scans were measured by three experienced surgeons independently. The DCL was defined in the coronal plane as a tangent to the dorsal femoral cortex located 75 mm above the joint line in the frontal plane. The difference between sTEA and DCL was calculated. Descriptive statistics and angulation correlations were generated for the sTEA and DCL, as well as for the distribution of measurement error for intra- and inter-rater reliability. Results. The external rotation of the DCL to the sTEA was a mean of 9.47° (SD 3.06°), and a median of 9.2° (IQR 7.45° to 11.60°), with a minimum value of 1.7° and maximum of 16.3°. The measurements of the DCL demonstrated very good to excellent test-retest and inter-rater reliability coefficients (intraclass correlation coefficient 0.80 to 0.99). Conclusion. This study reveals a correlation between the sTEA and the DCL. Overall, 10° of external rotation of the dorsal femoral cortical bone to the sTEA may serve as a reliable landmark for initial position of the femoral component. Surgeons should be aware that there are outliers in this study in up to 17% of the measurements, which potentially could result in deviations of femoral component rotation. Cite this article: Bone Jt Open 2024;5(12):1067–1071

Aims

Electromagnetic induction heating has demonstrated in vitro antibacterial efficacy over biofilms on metallic biomaterials, although no in vivo studies have been published. Assessment of side effects, including thermal necrosis of adjacent tissue, would determine transferability into clinical practice. Our goal was to assess bone necrosis and antibacterial efficacy of induction heating on biofilm-infected implants in an in vivo setting.

The December 2024 Oncology Roundup³⁶⁰ looks at: Non-reversed great saphenous vein grafts for vascular reconstruction after resection of lower limb sarcoma; Detrimental effects of COVID-19 pandemic on patients with limb bone sarcoma: reference centre experience; Whole-body staging guidelines in sarcoma; Intraoperative marrow margin frozen section in limb bone sarcoma resection; Vacuum-assisted closure and paediatric oncological limb salvage; Treatment differences and long-term outcomes in adults and children with Ewing’s sarcoma; Survival, complications, and functional outcomes of uncemented distal femoral endoprosthesis with short, curved stem for patients with bone tumours.

The December 2024 Trauma Roundup³⁶⁰ looks at: Percutaneous lumbopelvic fixation is effective in the management of unstable transverse sacral fractures; A systematic review on autologous matrix-induced chondrogenesis (AMIC) for chondral knee defects; Stable clinical and radiological outcomes at medium and over five-year follow-up of calcaneus fracture open reduction internal fixation using a sinus tarsi approach; Right or left? It might make a difference; Suprapatellar versus infrapatellar tibial nailing – is there a difference in anterior knee pain and function?; Can patients safely weightbear following ankle fracture fixation?; Anterior-to-posterior or a plate fixation for posterior malleous fractures?; Audio distraction for traction pin insertion: a prospective randomized controlled study; Is intramedullary nailing of femoral diaphyseal fractures in the lateral decubitus position as safe and effective as on a traction table?

Hip fractures pose a major global health challenge, leading to high rates of morbidity and mortality, particularly among the elderly. With an ageing population, the incidence of these injuries is rising, exerting significant pressure on healthcare systems worldwide. Despite substantial research aimed at establishing best practice, several key areas remain the subject of ongoing debate. This article examines the latest evidence on the place of arthroplasty in the surgical treatment of hip fractures, with a particular focus on the choice of implant, the use of cemented versus uncemented fixation, and advances in perioperative care.

Cite this article: Bone Joint J 2024;106-B(12):1372–1376.

As advancements in total knee arthroplasty progress at an exciting pace, two areas are of special interest, as they directly impact implant design and surgical decision making. Knee morphometry considers the three-dimensional shape of the articulating surfaces within the knee joint, and knee phenotyping provides the ability to categorize alignment into practical groupings that can be used in both clinical and research settings. This annotation discusses the details of these concepts, and the ways in which they are helping us better understand the individual subtleties of each patient’s knee.

Cite this article: Bone Joint J 2024;106-B(12):1363–1368.

Aim. This retrospective study evaluated the outcome of treatment for unhealed fracture-related infections (FRI). Methods. We identified a consecutive, single-centre cohort of patients having treatment for an FRI Consensus confirmed FRI. All fractures were unhealed at the time of treatment. Patients were followed up for at least one year. Successful outcome was a healed fracture without recurrent infection. Lack of union, persistent infection and/or unplanned reoperation defined failure. Results. Demographics: 183 patients (184 FRIs) with mean age 52.1 years (range 17-96) were treated and followed up for a mean of 2.8 years (range 1-9.4). Mean duration of FRI was 1.1 years with 65 (35.5 %) presenting within 6 months of injury. 118 patients had established infected non-union. FRI was most frequent in the tibia (74), femur (48) and humerus (24). 171 patients were BACH Complex. 75.5% of FRIs were culture positive, with Staph. aureus being the most frequent organism. Polymicrobial infection and Gram negative cultures were common (25.5% and 33.6%). Treatment: 98.3% of surgeries were performed in one stage with just 3 planned 2-stage procedures (2 endoprosthetic replacements and 1 free fibular flap). No bone graft was used in any surgery and all wounds were closed at first operation. 48 cases (26%) required flap coverage (29 free flaps and 19 local flaps). Local antibiotics were used in 124 cases (67.4%) of primary surgeries. All patients had sampling, debridement, systemic antibiotics and wound closure. 40 (21.7%) had DAIR, 31 (16.8%) had new internal fixation and 105 (57.1%) had external fixation (including 79 Ilizarov fixators). Outcomes: After primary surgery, 84.6% of all patients were infection-free and 77.2% had united. After further surgery, 98.8% were infection-free and 98.1% had united. External fixation techniques achieved infection eradication in 89.1% compared to 71.7% with any internal fixation (p=0.005). Primary internal fixation achieved union in 81.7% compared to 74.3% with external fixation (p=0.27). Secondary surgery after external fixation was mainly docking site fixation. Conclusion. Unhealed FRIs present a difficult challenge for treatment. This large series demonstrated that single-stage treatment, without bone grafting, gave acceptable results with few reoperations. Primary external fixation gave more certainty of infection eradication but required more reoperations to secure union. However, this difference in reoperation was not statistically significant. We strongly advocate managing these patients with a multidisciplinary team which can treat all aspects of the condition

Aim. Decubitus ulcers are found in approximately 4.7% of hospitalized patients, with a higher prevalence (up to 30%) among those with spinal cord injuries. These ulcers are often associated with hip septic arthritis and/or osteomyelitis involving the femur. Girdlestone resection arthroplasty is a surgical technique used to remove affected proximal femur and acetabular tissues, resulting in a substantial defect. The vastus lateralis flap has been employed as an effective option for managing this dead space. The aim of this study was to evaluate the long-term outcomes of this procedure in a consecutive series of patients. Method. A retrospective single-center study was conducted from October 2012 to December 2022, involving 7 patients with spinal cord injuries affected by chronic severe septic hip arthritis and/or femoral head septic necrosis as a consequence of decubitus ulcers over trochanter area. All patients underwent treatment using a multidisciplinary approach by the same surgical team (orthopedic and plastic surgeons) along with infectious disease specialists. The treatment consisted of a one-stage procedure combining Girdlestone resection arthroplasty with unilateral vastus lateralis flap reconstruction, alongside targeted antibiotic therapy. Complications and postoperative outcomes were assessed and recorded. The mean follow-up period was 8 years (range 2-12). Results. Of the 7 patients, 5 were male and 2 were female, with a mean age of 50.3 years at the time of surgery. Minor wound dehiscence occurred in 28.6% of the flap sites, and 2 patients required additional revisional procedures—one for hematoma and the other for bleeding. There were no instances of flap failure, and complete wound healing was achieved in an average of 32 days (range 20-41), with the ability to load over the hip area. No cases of infection recurrence or relapse were observed. Conclusions. An aggressive surgical approach is strongly recommended for managing chronic hip septic arthritis or proximal femur osteomyelitis in patients with spinal cord injuries. A single-stage procedure combining Girdlestone resection arthroplasty with immediate vastus lateralis muscle flap reconstruction proves to be an effective strategy for dead space management and localized antibiotic delivery through the vastus muscle, giving reliable soft tissue coverage around the proximal femur to avoid the recurrence of pressure ulcers. The implementation of a standardized multidisciplinary protocol contributes significantly to the success of reconstruction efforts

Aim. Aim of this study was to establish the first clinical results after implantation of ultrathin silver-polysiloxane-coated. 1. plates in the treatment of infected non-union of the femoral shaft. Method. As part of the REFECT study, a prospective, non-interventional analysis was conducted encompassing all patients who received internal stabilization with a silver-coated. 1. plate from 01/2023 to 09/2024 as part of the treatment for infected non-union of the femur. Standardized clinical follow-ups including PROMs (WOMAC-Index, LEF-S, EQ-5D, VAS) and X-rays were performed 3, 6, 12 (and 24) months postoperatively. For comparison, a retrospective analysis of 76 patients with infected femoral non-union, who had received a stabilization with an uncoated plate in the past 10 years, was performed. Results. The mean follow-up of the 8 included patients (mean bone defect: 3.6 cm) was 9 months (as of 04/24). Multiresistant bacteria were found in the intraoperative samples of 5 patients. The concentration of silver ions in blood serum reached a maximum of 0.014 mg/l in the laboratory controls. All patients showed a positive healing process with no sign of re-infection and no adverse procedure-associated events. Full weight bearing was achieved after an average of 4 months (n=6) with improved WOMAC-, LEF-S-, EQ-5D and VAS-score at 1-year FU. In the reference group (uncoated, mean FU: 3.5 years), there was a re-infection rate of 25 %, mostly in the first 2 years. Difficult-to-treat bacteria were detected in 22%, multiresistant Staph. epidermidis in 28% of cases. Conclusions. -. The silver-coated. 1. implants showed good biocompatibility with no evidence of procedure-associated complications. -. The use of silver-coated. 1. implants could reduce the risk of re-infection. -. Further clinical data with longer follow-up are needed to assess the long-term value of the procedure

Introduction. The evaluation of treatment modalities for distal femur periprosthetic fractures (DFPF) post-total knee arthroplasty (TKA) has predominantly focused on functional and radiological outcomes in existing literature. This study aimed to comprehensively compare the functional and radiological efficacy of locking plate (LP) and retrograde intramedullary nail (IMN) treatments, while incorporating mortality rates. Method. Twenty patients (15 female, 5 male) with a minimum 24-month follow-up period, experiencing Lewis-Rorabeck type-2 DFPF after TKA were included. These patients underwent either LP (n=10) or IMN (n=10). The average follow-up duration was 48 months (range: 24–192). Treatment outcomes, including functional scores, alignment, union time, complications, and mortality rates, were assessed and compared between LP and IMN groups. Clinical examination findings pre-treatment and at final follow-up, along with two-way plain radiographs, were utilized. Statistical analyses comprised Student's t-test and Kaplan-Meier survival analysis with a 95% confidence interval. Result. At final follow-up, the LP group demonstrated a mean Knee Society score of 67.2 ± 16.1, while the IMN group exhibited a score of 72.8 ± 9.4(P = 0.58). No statistically significant differences were observed in alignment between the groups[aLDFA (anatomical lateral distal femoral angle), P = 0.31; aPDFA (anatomical posterior distal femoral angle), P = 0.73]. The mean time to union was 3.7 ± 0.8 months for LP and 3.9 ± 0.6 months for IMN (P = 0.62). Complications such as infection occurred in 1 LP patient, and non-union was observed in 2 LP patients, while no complications were noted in IMN group(P < 0.01). Mortality rates were notably lower in the IMN group compared to the LP group across various time intervals. Conclusion. Both LP and IMN treatments yielded similar functional scores, alignment, and union time for DFPF post-TKA. However, the lower incidence of complications and mortality rates associated with IMN treatment suggest its superiority in managing DFPF following TKA

Introduction. Accurate assessment of alignment in pre-operative and post-operative knee radiographs is important for planning and evaluating knee replacement surgery. Existing methods predominantly rely on manual measurements using long-leg radiographs, which are time-consuming to perform and are prone to reliability errors. In this study, we propose a machine-learning-based approach to automatically measure anatomical varus/valgus alignment in pre-operative and post-operative standard AP knee radiographs. Method. We collected a training dataset of 816 pre-operative and 457 one-year post-operative AP knee radiographs of patients who underwent knee replacement surgery. Further, we have collected a separate distinct test dataset with both pre-operative and one-year post-operative radiographs for 376 patients. We manually outlined the distal femur and the proximal tibia/fibula with points to capture the knee joint (including implants in the post-operative images). This included point positions used to permit calculation of the anatomical tibiofemoral angle. We defined varus/valgus as negative/positive deviations from zero. Ground truth measurements were obtained from the manually placed points. We used the training dataset to develop a machine-learning-based automatic system to locate the point positions and derive the automatic measurements. Agreement between the automatic and manual measurements for the test dataset was assessed by intra-class correlation coefficient (ICC), mean absolute difference (MAD) and Bland-Altman analysis. Result. Analysing the agreement between the manual and automated measurements, ICC values were excellent pre-/post-operatively (0.96, CI: 0.94-0.96) / (0.95, CI: 0.95-0.96). Pre-/post-operative MAD values were 1.3°±1.4°SD / 0.7°±0.6°SD. The Bland-Altman analysis showed a pre-/post-operative mean difference (bias) of 0.3°±1.9°SD/-0.02°±0.9°SD, with pre-/post-operative 95% limits of agreement of ±3.7°/±1.8°, respectively. Conclusion. The developed machine-learning-based system demonstrates high accuracy and reliability in automatically measuring anatomical varus/valgus alignment in pre-operative and post-operative knee radiographs. It provides a promising approach for automating the measurement of anatomical alignment without the need for long-leg radiographs. Acknowledgements. This research was funded by the Wellcome Trust [223267/Z/21/Z]

Introduction. Three-dimensional (3D) morphological understanding of the hip joint, specifically the joint space and surrounding anatomy, including the proximal femur and the pelvis bone, is crucial for a range of orthopedic diagnoses and surgical planning. While deep learning algorithms can provide higher accuracy for segmenting bony structures, delineating hip joint space formed by cartilage layers is often left for subjective manual evaluation. This study compared the performance of two state-of-the-art 3D deep learning architectures (3D UNET and 3D UNETR) for automated segmentation of proximal femur bone, pelvis bone, and hip joint space with single and multi-class label segmentation strategies. Method. A dataset of 56 3D CT images covering the hip joint was used for the study. Two bones and hip joint space were manually segmented for training and evaluation. Deep learning models were trained and evaluated for a single-class approach for each label (proximal femur, pelvis, and the joint space) separately, and for a multi-class approach to segment all three labels simultaneously. A consistent training configuration of hyperparameters was used across all models by implementing the AdamW optimizer and Dice Loss as the primary loss function. Dice score, Root Mean Squared Error, and Mean Absolute Error were utilized as evaluation metrics. Results. Both the models performed at excellent levels for single-label segmentations in bones (dice > 0.95), but single-label joint space performance remained considerably lower (dice < 0.87). Multi-class segmentations remained at lower performance (dice < 0.88) for both models. Combining bone and joint space labels may have introduced a class imbalance problem in multi-class models, leading to lower performance. Conclusion. It is not clear if 3D UNETR provides better performance as the selection of hyperparameters was the same across the models and was not optimized. Further evaluations will be needed with baseline UNET and nnUNET modeling architectures

Introduction

Distal femur fractures around a total knee arthroplasty (TKA) are a growing problem for orthopaedic surgeons. The purpose of this study was to identify risks of reoperation for nonunion following open reduction and internal fixation of TKA periprosthetic distal femur fractures (PDFF).

Introduction. Current treatments of rotational deformities of long bones in children are osteotomies and fixations. In recent years, the use of guided growth for correction of rotational deformities has been reported in several pre-clinical and clinical studies. Various techniques have been used, and different adverse effects, like growth retardation and articular deformities, have been reported. We tested a novel plate concept intended for correction of rotational deformities of long bones by guided growth, with sliding screw holes to allow for longitudinal growth, in a porcine model. Method. Twelve, 12-week-old female porcines were included in the study. Surgery was performed on the left femur. The right femur was used as control. Plates were placed distally to induce external rotation, as longitudinal growth occurred. CT-scans of the femurs were processed to 3-D models and used for measuring rotation. Result. The plates rotated as intended in all 12 porcines. One porcine was excluded due to congenital deformity of the proximal part of the femurs. Two porcines had cut-out of the proximal screw on the lateral side, observed at the end of the intervention. These two porcines were included in the results. We observed a Δrotation of 5.7° ± 2° in external direction (CI: 3.7°– 7.7°). ΔFemur length was -0.4 cm [-0.7 cm – 0 cm] equal to 1.5% shortening of the operated femur. No significant difference was observed in coronal or sagittal plane. Conclusion. Significant external rotation was achieved with minimal effect on longitudinal growth. While the use of guided growth for correction of rotational deformities is already being used clinically, it is still to be considered an experimental procedure with sparse evidence. This study shows promising results for the feasibility of the method in a large animal model and is an important first step in validating the technique and detecting possible adverse effects, before future clinical studies

Introduction. Understanding knee joint biomechanics is crucial, but studying Anterior cruciate ligament (ACL) biomechanics in human adolescents is challenging due to limited availability cadaveric specimens. This study aims to validate the adolescent porcine stifle joint as a model for ACL studies by examining the ACL's behavior under axial and torsion loads and assessing its deformation rate, stiffness, and load-to-failure. Methods. Human knee load during high-intensity sports can reach 5-6 times body weight. Based on these benchmarks, the study applied a force equivalent to 5-times body weight of juvenile porcine samples (90 pounds), estimating a force of 520N. Experiments involved 30 fresh porcine stifle joints (Yorkshire breed, Avg 90 lbs, 2-4 months old) stored at -22°C, then thawed and prepared. Joints were divided into three groups: control (load-to-failure test), axially loaded, and 30-degree torsion loaded. Using a servo-hydraulic material testing machine, the tibia's longitudinal axis was aligned with the load sensor, and specimens underwent unidirectional tensile loading at 1 mm/sec until rupture. Data on load and displacement were captured at 100 Hz. Results. One-way ANOVA showed statistically significant differences in maximum failure force among loading conditions (p = 0.0039). Post hoc analysis indicated significant differences between the control and 500N (non-twisted) groups (p = 0.014) and between the control and 500N (twisted) groups (p = 0.003). However, no significant difference was found between 500N (non-twisted) and 500N (twisted) groups (p = 0.2645). Two samples broke from the distal femur growth plates, indicating potential growth plate vulnerability in adolescent porcines. Conclusions. The study validates the adolescent porcine stifle joint as a suitable model for ACL biomechanical research, demonstrating that torsional loads are as damaging to the ACL's integrity as equivalent axial loads. It also highlights the potential vulnerability of growth plates in younger populations, reflected in the porcine model

Introduction. The non-union of long bones poses a substantial challenge to clinicians and patients alike. The Ilizarov fixation system and Limb Reconstruction System (LRS), renowned for their versatility in managing complex non-unions. The purpose of this retrospective study was to assess the outcomes of acute docking with the bone peg-in-bone technique for the management of non-unions of long bones. The study seeks to evaluate its effectiveness in achieving complete bony union, preserving limb length and alignment, correcting existing deformities, and preventing the onset of new ones. Method. A retrospective analysis of 42 patients was done with infected and non-infected non-unions of long bones who received treatment at a tertiary care hospital between April 2016 to April 2022. We utilized the Association for the Study and Application of Methods of the Ilizarov (ASAMI) scoring system to assess both bone and functional outcomes and measured mechanical lateral distal femoral angle (mLDFA) for the femur and the medial proximal tibial angle (MPTA) for the tibia. Result. In our retrospective study involving 42 patients, a total of 30 patients had post debridement gap of >2 cm and average gap of 4.54 cm (range 1 – 13 cm) and therefore underwent corticotomy and lengthening. The average external fixation time was 6.52 (range 4 – 11 months) and average external fixation index of 2.08 (range 0.4 – 4.5 months/cm). The ASAMI scoring system showed bone result of 38 excellent, 3 good and 1 fair. Functional result of 40 excellent and 2 good outcomes. The post op mLDFA and MPTA were in normal range except in 3 patients which not statistically significant. Conclusion. In conclusion, the use of acute docking provides several advantages such as promoting early fracture healing, increasing stability, shortening treatment time, reducing the number of surgical procedures and reduced number of complications

Introduction. Research studies have established mathematical correlations between the lengths of bone segments and the possible biomechanical implications of these correlations. The Lucas sequence comprises a series of integers that adhere to the same recurrence relation as the Fibonacci sequence; it differs in that it can start with any two initial integers. The purpose of this study is to determine whether segmental lengths of the foot height, tibia, femur, and upper body follow a Lucas sequence pattern. Method. This was a retrospective radiographic review of patients who underwent full-body EOS scans. The AP scan was used to measure standing foot height (Ft), tibial length (T), femoral length (Fe), upper body length (UB), and full body length. A linear regression test was performed to determine whether a Lucas sequence-based relationship exists between Ft + T and Fe, and between T + Fe and UB. Result. The regression for the relationship between Ft + T and Fe for the entire cohort (R= 0.82, R2= 0.70), the female subset (R= 0.94, R2= 0.88) and the male subset (R= 0.75, R2= 0.57), all demonstrated a strong positive correlation between Ft + T and Fe and showed that Ft + T is a likely predictor of Fe. The regression test for the entire cohort demonstrated a moderately positive correlation between T + Fe and UB (R= 0.41, R2= 0.17, F(1, 145) = 29.42, p= 2.4E-07). A stronger correlation was found for the relationship between T + Fe and UB (R= 0.57, R2= 0.32, F(1, 35) = 16.64, p= 2.5E-05) for the female subset relative to the male subset (R= 0.20, R2= 0.038, F(1, 35) = 4.37, p= 0.04). Conclusion. This study demonstrates that total height is made up of sequential segments whose lengths approximate a Lucas series. The Fibonacci sequence is therefore once again implicated in human body proportions