Platelet-Rich Plasma, Mesenchymal Stem Cell, and Non-metallic Suture-Based Fixation Technique in a Patellar Fracture Nonunion: A Technical Note and Systematic Review

Based on the diamond concept, application of platelet-rich plasma in the treatment of aseptic femoral shaft nonunion: A retrospective controlled study on 66 patients

BACKGROUND

Biologics, particularly platelet-rich plasma (PRP), have gained attention for promoting bone healing. This study assesses the efficacy of PRP-enhanced therapy in treating aseptic femoral shaft nonunion.

METHODS

This retrospective study analyzed patients who underwent femoral fracture nonunion revision surgery at a high-level trauma center between January 2021 and April 2024. Patients were divided into two groups: Group 1 (PRP-enhanced) and Group 2 (non-PRP). Group 1 received internal fixation with auxiliary plate reinforcement, PRP-enriched grafts, and bioactive center creation. The primary endpoint was bone healing rate and time to healing; secondary endpoints included lower limb function, pain scores, complications, and risk factors for nonunion at final follow-up.

RESULTS

Sixty-six patients were included (25 in Group 1, 41 in Group 2). At final follow-up, all patients in Group 1 healed, while 80.49 % of Group 2 healed (p = 0.049). The average healing time was shorter in Group 1 (7.61 months) compared to Group 2 (11.19 months) (p < 0.001). Group 1 had superior lower limb function and pain scores (p < 0.001). Long-term smoking (OR = 9.47, 95 % CI 1.39-64.51, P = 0.022) and inappropriate post-operative weight bearing (OR = 7.62, 95 % CI 1.12-51.57, P = 0.038) were identified as risk factors for nonunion.

CONCLUSION

In nonunion revision surgery, PRP-enhanced therapy significantly improves bone healing rates, reduces healing time, and carries fewer safety risks than traditional bone grafting. It offers an effective approach for nonunion treatment and provides a standardized clinical application for PRP in fracture nonunion surgeries.

Separate vertical wiring versus conventional tension band fixation for inferior pole patellar fractures: a prospective cohort study on postoperative patella baja and functional outcomes

OBJECTIVE

To compare the clinical efficacy of the separate vertical wiring (SVW) technique and conventional tension band fixation in managing AO/OTA type A1 inferior pole patellar fractures, focusing on postoperative patella baja incidence and functional recovery.

METHODS

From January 2019 to January 2023, 242 patients with AO/OTA A1 inferior pole patellar fractures undergoing surgical treatment were assigned to the SVW group (n = 117) or tension band (TB) group (n = 125). The primary outcome was the incidence of patella baja (Insall-Salvati index < 0.8) at the 12-month follow-up. Secondary outcomes included knee range of motion (ROM), Böstman functional score, and complications.

RESULTS

The SVW group demonstrated a significantly lower incidence of patella baja compared to the TB group (25.6% vs. 52.1%, P < 0.001), with higher mean (Insall-Salvati index) ISI values (0.87 ± 0.16 vs. 0.76 ± 0.12, P < 0.01). Knee ROM was superior in the SVW group (124.0°±14.2° vs. 119.9°±12.4°, P = 0.017), though no significant difference was observed in Böstman scores (25.1 ± 3.5 vs. 24.6 ± 3.6, P = 0.33). The overall complication rate was 5.8% (14/242), primarily comprising surgical site infections (3.5%, 8/242: 1.2% superficial, 2.1% deep), fixation failure (1.2%, 3/242), and nonunion (0.8%, 2/242). Notably, soft tissue irritation occurred exclusively in the TB group (8.8%, 11/125 vs. 0% in SVW; P = 0.005).

CONCLUSION

The SVW technique significantly reduces the risk of patella baja and improves knee range of motion by optimizing vertical tension distribution, establishing it as a biomechanically superior fixation strategy for AO/OTA A1 inferior pole patellar fractures. These findings support SVW as a first-line treatment for such complex injuries.

Case Report: Based on the diamond theory, successful treatment of stubborn tibial nonunion after six surgeries using PRP-augmented therapy: a case report and literature review

Background

The treatment of stubborn tibial nonunion remains a significant challenge. This case report describes a patient who underwent six surgeries and was treated using a stepwise surgical approach based on the diamond theory. The application of platelet-rich plasma (PRP) enhanced autologous iliac bone grafting combined with locked compression plate fixation ultimately achieved successful healing. This study also reviews relevant literature to explore the treatment experiences and outcomes of similar cases.

Patient and methods

A middle-aged Asian male with severe heart disease underwent five failed surgeries, including two autologous bone graft procedures. Clinically, he presented with right calf pain, poor soft tissue condition on the anterior medial tibia, and signs of nonunion. During the sixth surgery, we applied a stepwise surgical procedure based on the diamond theory, achieving excellent clinical and bone healing, as well as satisfactory limb function at a follow-up of 11.3 months post-operation.

Conclusion

We utilized a stepwise surgical procedure based on the diamond theory: locked compression plate internal fixation, PRP-enhanced structural autologous iliac bone grafting, and bioactive center creation techniques, providing a strong and stable mechanical and superior biological environment for the nonunion site.

Does protruding headless cannulated screw reduce fixation stability in tension band wiring technique for patella fractures? a biomechanical study

BACKGROUND

The selection of an implant is a critical factor in the surgical treatment of patella fractures due to the risk of various complications, such as non-union, implant failure, and irritation. The present study evaluated and compared the biomechanical strength of headless cannulated screws about screw length using the tension band wiring technique.

METHODS

Forty-eight sawbone patellas with transverse fractures were divided into three fixation groups based on the screw length used in tension band wiring. Overall, three different fixation groups were determined: Group 1 (recessed headless cannulated screw fixation), Group 2 (full-length headless cannulated screw fixation), and Group 3 (protruding headless cannulated screw fixation). A setup was used to simulate a knee with a flexion angle of 60 degrees. Specimens underwent biomechanical testing under axial traction (static test) and cyclic loading (dynamic test). Displacements at 300 Newtons (N), loads at 2 millimetres (mm) displacement, and failure loads were documented for each sample in the static test. In the dynamic test protocol, 10,000 repetitive cycles were performed under physiological load between 100 and 300 N, and final displacements were recorded.

RESULTS

There were significant differences in the loads achieved at 2 mm displacement levels, and Group 3 demonstrated lower force values compared to other constructs in the static test (P = 0.003). All groups revealed similar displacements at 300 N and failure load values under axial traction. In the dynamic test, Group 3 had significantly higher fracture displacement under cyclic loading compared to the other specimens (P = 0.006).

CONCLUSIONS

This study found headless cannulated screws for transverse patella fracture fixation provide sufficient stability; however, protruding headless screws reduce the fixation strength. Recessed or full-length screws may improve stability and bony healing, potentially preventing complications in patella fractures.

LEVEL OF EVIDENCE

Biomechanical study N/A.

Risk factors for surgical site infection after patellar fracture surgery in the elderly

BACKGROUND

Patellar fractures are a common knee injury among elderly patients, with a high risk of developing surgical site infections (SSI) postoperatively, which severely affects patient prognosis and quality of life. Elderly patients are more susceptible to SSI due to various factors such as decreased immune function and chronic diseases. Therefore, identifying the risk factors for SSI is of great clinical significance for prevention.

OBJECTIVE

This study aims to analyze the risk factors for postoperative SSI in elderly patients with patellar fractures, providing a basis for developing more effective clinical prevention and treatment strategies.

METHODS

This retrospective study collected data from 856 elderly patients who underwent patellar fracture surgery at Baoding First Central Hospital between January 2017 and December 2023. Patients were divided into SSI and non-SSI groups based on the occurrence of SSI, and their demographic data, comorbidities, and laboratory results were analyzed. Logistic regression was used to identify independent risk factors for SSI, and ROC curve analysis was conducted to determine the optimal cutoff point for predictive indicators.

RESULTS

The incidence of SSI was found to be 2.1%. Univariate analysis showed that BMI, surgical delay, diabetes, hematocrit (HCT), and albumin (ALB) were significantly associated with SSI. Logistic regression analysis further confirmed that BMI (p = 0.043), surgical delay (p = 0.000), HCT (p = 0.038), ALB (p = 0.015), and diabetes (p = 0.022) were independent risk factors for SSI. ROC curve analysis indicated that the optimal cutoff points for BMI, HCT, and ALB were 25.39 kg/m2, 35.62%, and 39.3 g/L, respectively, with an AUC of 0.794 for the combined predictive indicators.

CONCLUSION

High BMI, surgical delay, diabetes, low HCT, and low ALB are independent risk factors for postoperative SSI in elderly patients with patellar fractures. Preoperative management targeting these high-risk factors, such as optimizing patient weight, controlling diabetes, and improving nutritional status, can effectively reduce the incidence of SSI and improve postoperative outcomes. Future multicenter studies may further validate these findings and provide additional prevention strategies.

"Tension band wiring first" -an easy, fast and reproducible technique to reduce patellar fractures, a retrospective comparative study with traditional reduction technique

OBJECTIVE

To evaluate intraoperative and early postoperative clinical outcomes using the "tension band wiring first technique" to reduce C type patellar fractures.

METHODS

Sixty-four patients with C type fractures were enrolled in this study. Thirty-four patients underwent open reduction and internal fixation (ORIF) surgeries using the traditional reduction technique by pointed clamps (TRT group). The other thirty patients received the patellar fracture reduction using the "Tension band wiring first technique" (TBWFT group). All patellar fractures were treated with a cable tension band and a cerclage cable. The duration of intraoperative procedure and X-ray exposure times were recorded. All patients were followed up at 1, 3, 6, and 12 months. Bone union time was recorded. The articular surface steps of the patellas were measured. After surgery, range of motion (ROM) of the knee, and complications were evaluated, and patellar function was evaluated using the Lysholm knee scores and Böstman scores.

RESULTS

When compared to TRT group, the "Tension band wiring first technique" significantly reduced the intraoperative time and X-ray exposure times and tended to reduce the articular surface steps, though without statistical significance. In the two groups, there was no significant difference in bone union time, ROM, complications and patellar function.

CONCLUSION

The utilization of "Tension band wiring first technique" proved to be a straightforward, expeditious, and reproducible technique for reducing patellar fracture in comparison to the conventional reduction technique utilizing pointed clamps. Further studies are required to ensure the generalizability of these findings to additional patient populations at other institutions.

Platelet-rich plasma enhances rib fracture strength and callus formation in vivo

BACKGROUND

Rib fractures are a common traumatic injury affecting more than 350,000 patients a year. Early stabilization has shown to be effective in reducing pulmonary complications. Platelet-rich plasma (PRP) is a growth factor-rich blood product known to improve soft tissue and bone healing. We hypothesized that the addition of PRP to a rib fracture site would accelerate callus formation and improve callus strength.

METHODS

Platelet-rich plasma was isolated from pooled Lewis rat blood and quantified. Thirty-two Lewis rats underwent fracture of the sixth rib and were treated with 100 μL PRP (1 × 106 platelets/μL) or saline. At 2 weeks, ribs were harvested and underwent a 3-point bend, x-ray, and microcomputed tomography, and callus sections were stained with 4',6-diamidino-2-phenylindole and Alcian blue and picrosirius red. At 6 weeks, ribs were harvested and underwent a 3-point bend test, x-ray, microcomputed tomography, and Alcian blue and picrosirius red staining.

RESULTS

At 2 weeks, PRP increased callus diameter (9.3 mm vs. 4.3 mm, p = 0.0002), callus index (4.5 vs. 2.1, p = 0.0002), bone volume/total volume (0.0551 vs. 0.0361, p = 0.0024), cellularization (2,364 vs. 1,196, p < 0.0001), and cartilage (12.12% vs. 3.11%, p = 0.0001) and collagen (6.64% vs. 4.85%, p = 0.0087) content compared with controls. At 6 weeks, PRP increased fracture callus diameter (5.0 mm vs. 4.0 mm, 0.0466), callus index (2.5 vs. 2.0, p = 0.0466), BV/TV (0.0415 vs. 0.0308, p = 0.0358), and higher cartilage (8.21% vs. 3.26%, p < 0.0001) and collagen (37.61% vs. 28.00%, p = 0.0022) content compared with controls. At 6 weeks, PRP samples trended toward improved mechanical characteristics; however, these results did not reach significance (p > 0.05).

CONCLUSION

Rib fractures are a common injury, and accelerated stabilization could improve clinical outcomes. Platelet-rich plasma significantly increased callus size, calcium deposition, and cartilage and collagen content at 2 and 6 weeks and trended toward improved strength and toughness on mechanical analysis at 6 weeks compared with controls, although this did not reach significance. These findings suggest that PRP may be a useful adjunct to accelerate and improve fracture healing in high-risk patients.

An innovative anti-rotation tension band wiring for treating transverse patellar fractures: finite element analysis and mechanical testing

BACKGROUND

The displacement and rotation of the Kirschner wire (K-wire) in the traditional tension band wiring (TBW) led to a high rate of postoperative complications. The anti-rotation tension band wiring (ARTBW) could address these issues and achieve satisfactory clinical outcomes. This study aimed to investigate the biomechanical performance of the ARTBW in treating transverse patellar fracture compared to traditional TBW using finite element analysis (FEA) and mechanical testing.

METHODS

We conducted a FEA to evaluate the biomechanical performance of traditional TBW and ARTBW at knee flexion angles of 20°, 45°, and 90°. Furthermore, we compared the mechanical properties under a 45° knee flexion through static tensile tests and dynamic fatigue testing. The K-wire pull-out test was also conducted to evaluate the bonding strength between K-wires and cancellous bone of two surgical approaches.

RESULTS

The outcome of FEA demonstrated the compression force on the articular surface of ARTBW was 28.11%, 27.32%, and 52.86% higher than traditional TBW at knee flexion angles of 20°, 45°, and 90°, respectively. In mechanical testing, the mechanical properties of ARTBW were similar to the traditional TBW. In the K-wire pull-out test, the pull-out strength of ARTBW was significantly greater than the traditional TBW (111.58 ± 2.38 N vs. 64.71 ± 4.22 N, P < 0.001).

CONCLUSIONS

The ARTBW retained the advantages of traditional TBW, and achieved greater compression force of articular surface, and greater pull-out strength of K-wires. Moreover, ARTBW effectively avoided the rotation of the K-wires. Therefore, ARTBW demonstrates potential as a promising technique for treating patellar fractures.

Tension band high-strength suture combined with absorbable cannulated screws for treating transverse patellar fractures: finite element analysis and clinical study

Objective: Few reports exist on the treatment of transverse patellar fractures (TPFs) using absorbable cannulated screws and high-strength sutures, and most screws and sutures lack good biomechanics and clinical trials. Therefore, this study aimed to demonstrate the biomechanical stability and clinical efficacy of tension-band high-strength sutures combined with absorbable cannulated screws (TBSAS) in treating TPFs (AO/OTA 34 C1). Methods: Finite element models of five internal fixation schemes were established: tension-band wire with K-wire (TBW), TBW with cerclage wire (TBWC), TBW with headless pressure screws (TBWHS), TBW with full-thread screws (TBWFS), and TBSAS. We comprehensively compared the biomechanical characteristics of the TBSAS treatment scheme during knee flexion and extension. Forty-one patients with TPFs in our hospital between January 2020 and August 2022 were retrospectively enrolled and divided into the TBSAS (n = 22) and TBWC (n = 19) groups. Clinical and follow-up outcomes, including operative time, visual analog scale (VAS) pain score, postoperative complications, Bostman score, and final knee range of motion, were compared between both groups. Results: Finite element analysis (FEA) showed that TBWHS and TBWFS achieved the minimum mean fracture interface relative displacement during knee flexion (45°, 0-500 N bending load) and full extension (0°, 0-500 N axial load). There was no significant difference between TBSAS (0.136 mm) and TBWC (0.146 mm) during knee flexion (500 N); however, TBSAS displacement was smaller (0.075 mm) during full extension (500 N). Furthermore, the stress results for the internal fixation and the patella were generally lower when using TBSAS. Retrospective clinical studies showed that the TBSAS group had a shorter operative time, lower VAS pain score at 1 and 2 months postoperatively, better Bostman knee function score at 3 and 9 months postoperatively, and better final knee joint motion than the TBWC group (all p < 0.05). There were five cases (26.3%) of internal fixation stimulation complications in the TBWC group. Conclusion: TBSAS demonstrated excellent safety and effectiveness in treating TPFs. It is sufficient to meet the needs of TPF fixation and early functional exercise and effectively reduces metal internal fixation-induced complications and secondary surgery-induced trauma.

Novel screw-cable integrated system(SCIS) for minimally invasive treatment of patella transverse fractures: a finite element analysis

BACKGROUND

The most recommended method for treating transverse patella fractures is modified tension band wiring (MTBW). However, the optimal instrument for use with MTBW is still undetermined. Hence, we aimed to design a novel screw-cable integrated system (SCIS) and compare its biomechanical characteristics with Kirschner-wire, SCIS, and Cable-Pin systems in treating transverse patellar fracture.

METHODS

A finite-element (FE) model of transverse patella fracture was created. The fracture model was fixed with either K-wire, SCIS, or Cable-pin. Different tension force loading (400 N and 800 N), direction(0° and 45°), and screw or K-wire depth(5 mm and 10 mm) were set. The maximum displacement of the fragment and maximum gap opening were measured by using FE analysis.

RESULTS

Compared with the K-wire and Cable-pin system, SCIS increased the stability of the fractured patella by reducing fragment displacement and gap opening. Under 400 N loading in the direction 45°, SCIS with screw placing at 5-mm depth reduced the maximum fragment displacement (0.43 mm) by 49.62% and 26%, respectively, compared with the K-wire (0.22 mm) and Cable-pin (0. 22 mm) group. Meanwhile, the gap opening in SCIS (0.05 mm) was reduced by 83% and 59.8% (0.05 to 0.18) compared with the K-wire (0.30 mm) and Cable-pin (0.18 mm) group.

CONCLUSION

SCIS demonstrated improved biomechanical stability for treating transverse patellar fractures compared to MTBW with Kirschner wire and the Cable-Pin system. Finite element analysis showed SCIS substantially reduced fracture fragment displacement and gap opening under various loading conditions.

A double-suture cerclage reduction technique with Nice knots for comminuted patella fractures (AO/OTA 34-C3)

BACKGROUND

Comminuted patella fractures place high demands on surgeons' surgical skills. We used a double-suture cerclage reduction with Nice knots as an intra-operative reduction technique to displaced comminuted patella fractures.

METHODS

Patients were divided into two groups by whether or not an intra-operative suture cerclage reduction technique was used. Fragments count, surgical time, quality of the reduction, and fracture healing time were recorded. The postoperative function was assessed by Böstman score and range of motion.

RESULTS

With the inclusion and exclusion criteria, 48 patients we included in the cohort between Sept. 2016 and Oct. 2021. The double-suture cerclage reduction technique with a Nice knot achieved a satisfactory reduction. When the number of fragments was over 5, this technique showed significant advantages in saving surgery time.

CONCLUSIONS

In this study, the double-suture cerclage reduction technique combined with the Nice knot shows significant advantages for displaced highly comminuted patella fractures. This technique simplifies the operation and saves surgical time, which is helpful for clinical practice.

Human Epidural AD-MSC Exosomes Improve Function Recovery after Spinal Cord Injury in Rats

Spinal cord injury (SCI) interferes with the normal function of the autonomic nervous system by blocking circuits between the sensory and motor nerves. Although many studies focus on functional recovery after neurological injury, effective neuroregeneration is still being explored. Recently, extracellular vesicles such as exosomes have emerged as cell-free therapeutic agents owing to their ability of cell-to-cell communication. In particular, exosomes released from mesenchymal stem cells (MSCs) have the potential for tissue regeneration and exhibit therapeutic effectiveness in neurological disorders. In this study, we isolated exosomes from human epidural adipose tissue-derived MSCs (hEpi AD-MSCs) using the tangential flow filtration method. The isolated exosomes were analyzed for size, concentration, shape, and major surface markers using nanoparticle tracking analysis, transmission electron microscopy, and flow cytometry. To evaluate their effect on SCI recovery, hEpi AD-MSC exosomes were injected intravenously in SCI-induced rats. hEpi AD-MSC exosomes improved the locomotor function of SCI-induced rats. The results of histopathological and cytokine assays showed that hEpi AD-MSC exosomes regulated inflammatory response. Genetic profiling of the rat spinal cord tissues revealed changes in the expression of inflammation-related genes after exosome administration. Collectively, hEpi AD-MSC exosomes are effective in restoring spinal functions by reducing the inflammatory response.

The clinical outcome of the reduction of the patellar inferior pole fracture with wire cerclage through a generated bone hole, in combination with patellar concentrator: a retrospective comparative study

OBJECTIVE

The patellar inferior pole fracture is typically comminuted. Hence, achieving firm fixation and early activity is highly challenging. In this article, we employed the method of wire cerclage through a generated bone hole to reduce the fracture. Our objective was to compare the clinical efficacy of patellar concentrator alone with a combination of cerclage and patellar concentrator in the treatment of patellar inferior pole fracture.

METHODS

We conducted a retrospective review of patients with patellar inferior pole fractures, who underwent patellar concentrator fixation only (the control group) or cerclage combined with patellar concentrator fixation (the experimental group), performed by a single surgeon, between July 2015 and October 2019. Our analysis included surgical indexes like7 aspects (fracture gap after operation, operation time, intra-operative blood loss, intra-operative number of C-arm fluoroscopies conducted, Insall-Salvati ratio calculated immediately after operation, initial range of motion on the 7th day after operation, and fracture healing time), as well as the Bostman score and complications recorded on 1-, 3-, 6-, and 12-month follow up post operation.

RESULTS

A total of 94 patients with patellar inferior pole fracture and a minimum 1-year follow up were recruited. Following operation, the control group had 33 (71.74%) patients with a fracture gap of 0-2 mm and 13 (28.26%) patients with a fracture gap greater than 2 mm (P = 0.002). Conversely, the experimental group had 46 (95.83%) patients with a fracture gap of 0-2 mm and 2 (4.17%) patients with a fracture gap greater than 2 mm (P = 0.002). Compared to the control group, the experimental group did not experience enhanced operation time or intra-operative blood loss (P = 0.811, P = 0.823). The Insall-Salvati ratio and initial range of motion in the experimental group were larger than the control group (P = 0.037, P = 0.000). Alternately, the number of intra-operative C-arm fluoroscopies conducted and fracture healing time of the experimental group were considerably less than the control group (P = 0.003, P = 0.000). Moreover, at 1-, 3-, 6-, and 12-month follow ups after operation, the Bostman scores of the experimental group were remarkably higher than the control group (P < 0.05). At 12 months post operation, 23 cases (50%) were classified as excellent, 22 cases (47.83%) were good, and 1 case (2.17%) was poor in the control group (P = 0.005). In the meantime, in the experimental group, 38 cases (79.17%) were deemed as excellent and 10 cases (20.83%) were good (P = 0.005). Lastly, complications were detected in 3 cases (6.52%; 1 case of internal fixation loss, 2 cases of hematoma) within the control group, and in 1 case(2.08%; marginal wound necrosis) within the experimental group. There was no wound infection, implant discomfort, or broken fixation in either group.

CONCLUSION

Managing the patellar inferior pole fracture with wire cerclage through a generated bone hole is both simple and effective. Moreover, an additional step of patellar concentrator fixation facilitates early functional exercise, with satisfactory clinical outcome.

Cell therapy for osteonecrosis of femoral head and joint preservation

Osteonecrosis of femoral head (ONFH) is a disease of the femoral head and can cause femoral head collapse and arthritis. This can lead to pain and gait disorders. ONFH has various risk factors, it is often progressive, and if untreated results in secondary osteo-arthritis. Biological therapy makes use of bone marrow concentrate, cultured osteoblast and mesenchymal stem cell (MSC) obtained from various sources. These are often used in conjunction with core decompression surgery. In this review article, we discuss the current status of cell therapy and its limitations. We also present the future development of biological approach to treat ONFH.