Clinical Comparative Study on the Treatment of Inferior Pole Fractures of Patella by Double-row Anchor Suture Bridge Technique Combined with Kirschner Wire Tension Band Internal Fixation

Objective: To investigate the method, technique and clinical efficacy of double-row anchor suture bridge technique in the treatment of inferior pole fractures of patella, and to compare it with traditional Kirschner wire tension band internal fixation. Methods: General information A total of 62 patients were enrolled in this study, including 35 males and 27 females, aged 31-80 years old, with an average of (53.2±4) years old. All the patients were divided into two groups by a random double-blind method: Group A (double-row anchor suture bridge technique group) and Group B (Kirschner wire tension band internal fixation group), with 32 cases and 30 cases in each group, respectively. The two techniques were performed by the same group of doctors to fix the fracture respectively, and the intraoperative bleeding, operation time, incidence of postoperative complications, knee function score, etc., were compared between the two techniques. Results: Group A (double-row anchor suture bridge technique group): operation time 56-80min, with an average of (60±10) min; intraoperative blood loss 30-56ml, with an average of (43±10) ml. All incisions healed in one stage and stitches were removed after 2 weeks. No complications such as incision infection, flap necrosis and nerve injury occurred. The average healing time of the fracture was 12 weeks. At the last follow-up, the Bostman score was (28.5±3.3), and the excellent rate was 93.7%. Group B (Kirschner wire tension band internal fixation group): operation time 54-76min, with an average of (56±10) min; intraoperative blood loss 31-50ml, with an average of (43±80) ml. One patient developed delayed incision healing postoperatively. Four patients experienced Kirschner wire withdrawal, one of which was accompanied by infection. Two patients were found to have mild separation of distal fracture fragments, despite the fracture being fine. The average healing time of the fracture was 13 weeks. At the last follow-up, the Bostman score was (23.5±3.3), and the excellent rate was 86.7%. Conclusion: Double-row anchor suture bridge technique is applied to inferior pole fractures of patella by virtue of its various effects, such as the complete preservation of the inferior pole fragments during the operation, satisfactory fracture reduction, firm fixation, and meeting patients’ requirements for early postoperative ambulation. This technology is superior to traditional Kirschner wire tension band internal fixation owing to its advantages of no need to take out the internal fixation, firm fixation, no need to worry about Kirschner wire withdrawal and fewer complications, and its clinical efficacy satisfaction rate is also better than traditional surgical methods. In short, double-row anchor suture bridge technique is an ideal surgical procedure for the treatment of the inferior pole fracture of patella with safety, reliability and high satisfaction.

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 followup 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 gapgreater than 2 mm(P=0.002). Conversely,the experimental grouphad46(95.83%)patients with a fracture gap of 0-2 mm and 2(4.17%) patients with a fracture gapgreater 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 conductedand 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 eithergroup.Conclusion: Managingthe 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.

Multifragmentary patellar fracture has a distinct fracture pattern which makes coronal split, inferior pole, or satellite fragments

The present study aimed to map the location and frequency of fracture lines on the coronal articular and sagittal planes in multifragmentary patellar fractures. 66 multifragmentary patellar fractures were digitally reconstructed using the 3D CT mapping technique. The coronal articular surface and midsagittal fracture maps were produced by superimposing each case over a single template. Each fracture line was classified based on the initial displacement and orientation. We evaluated the frequency and direction of the fracture line, coronal split fragment area, and satellite and inferior pole fragment presence. Coronal articular surface fracture mapping identified primary horizontal fracture lines between the middle and inferior one-third of the articular surface in 63 patients (95.4%). Secondary horizontal fracture lines running on the inferior border of the articular facet were confirmed (83.3%). Secondary vertical fracture lines creating satellite fragments were mostly located on the periphery of the bilateral facet. Midsagittal fracture mapping of primary and secondary horizontal fracture lines with the main coronal fracture line revealed a predominantly X-shaped fracture map. The consequent coronal split fragment and inferior pole fracture were combined in most cases. In conclusion, the multifragmentary patellar fracture has a distinct pattern which makes coronal split, inferior pole, or satellite fragments.

Anatomical Considerations for Appropriate Mini-plate Positioning in Open-Door Laminoplasty To Avoid Plate Impingement and Screw Facet Violation

Objective This study aimed to describe a safe zone for mini-plate positioning that can avoid instrument-related complications in laminoplasty. Methods The posterior surface length and inferior pole angle of the lateral mass were measured at each level using computed tomography. The safe zone was defined based on these measurements. Incidences of screw facet violation and plate impingement were recorded. Results Among 40 patients included, 15 (37.5%) had inappropriate plate positioning, causing screw facet violation or plate impingement, which more commonly occurred at distal (C5, C6) and proximal (C3, C4) levels, respectively. Lateral mass posterior surface length was shorter at the proximal levels, and the inferior pole angle of the lateral mass was smaller at the distal levels, signifying that the lateral mass became thin and long at the distal levels. Inserting the mini-plate with plate-to-lateral mass inferior pole distances of 4–5 mm and 5–6 mm at the C3–C5 and C6–C7 levels, respectively, would avoid instrument-related complications. Conclusion The risk of plate impingement was higher at the proximal level, whereas the risk of screw facet violation was higher at the distal level in open-door cervical laminoplasty. These risks coincide with anatomical differences at each level.

"Net cage" technique in the treatment of inferior pole patella fracture: a novel patella internal fixation technique

Objective Fractures of the inferior pole of the patella can cause the knee joint extensor mechanism disorder. The fracture fragments are usually small and comminuted. Therefore, there are certain difficulties in fixation. The purpose of this study is to observe the effect of the "Net cage" technique in the treatment of the inferior pole of the patella. Methods This is a retrospective study that included 16 cases of inferior patella fractures (AO/OTA 34-A1) who underwent the "Net cage" technique from March 2017 to June 2020. Collecting their medical records and follow-up results, measuring indicators include the surgical complications of the fixation method, knee joint function, the number of fluoroscopies, fracture healing, and the incidence of soft tissue stimulation. Results The fractures of all patients healed smoothly, and there were no complications such as failure of internal fixation and fracture of implants. The average number of intraoperative fluoroscopy was 5.56 times (range: 4-10 times); the average fracture healing time was 10.5 weeks (range: 8-14 weeks) ). No patients reported internal fixation-related soft tissue irritation. At the last follow-up, the knee function showed that the average ROM was 133.75° (range: 120°~140°); The average Bostman score was 27.94 points (range: 24-30 points). Conclusion "Net cage" technology for the treatment of inferior pole fractures of the patella has the advantages of reduced fluoroscopy, fixation and stability, early functional exercise, and better knee joints after surgery.

Clinical and Radiographic Differentiation of Pediatric Patellar Sleeve Fractures and Other Inferior Pole Pathologies (165)

Objectives: Inferior pole patellar sleeve fractures (PSF) are rare injuries that occur in skeletally immature patients with sparse literature on the diagnosis, management, and outcomes of this injury. Diagnosis of PSF can be difficult based on radiographs alone, as only a small bony fragment is often seen. Consequently, PSFs may be missed or falsely diagnosed as an inferior pole fracture (IPF) or Sinding-Larson-Johansson syndrome (SLJS) possibly leading to improper treatment and poor outcomes (Figure 1). The objective of this study was to evaluate and compare clinical and radiographic features of patients with PSF, IPF and SLJS to help improve diagnostic accuracy. Methods: This was a retrospective review of skeletally immature patients diagnosed with inferior pole patellar pathology between 2011-2019 at a single urban academic center. Patients were identified using both International Classification of Diseases 9th and 10th edition (ICD-9 and ICD-10) codes and Current Procedural Terminology (CPT) codes. Data from medical records (demographics, injury mechanism and physical exam) and lateral knee radiographs (fragment size, fragment displacement, number of fragments, Insall-Salvati, Caton-Deschamps, pre-patellar effusion, intra-articular effusion) was collected. ANOVA, Student’s t-test and Fisher’s exact test were used for comparisons between the three groups. Statistical significance was determined at p<0.05. This study was approved by our institutional review board. Results: A total of 125 patients were included: 82% male, average age 10.7 years (SD 2), 16 PSF, 51 IPF, 58 SLJS patients. There were no significant differences in patient demographics between the three groups (Table 1). Only 24% of SLJS patients presented with acute trauma compared to 100% of the PSF and IPF patients. Fewer PSF patients had an intact straight leg raise (37.5%) compared to IPF (94.1%) and SLJS (98.3%) (p<0.001). SLJS patients were less likely to present with knee swelling (41.4%) compared to PSF (93.8%) and IPF (94.1%) (p<0.001) . Knee effusion was more frequently seen in PSF (81.2%) compared to IPF (37.3%) and SLJS (3.4%) (p<0.001). More patients with SLJS were able to bear weight (87.9%) compared to IPF (11.8%) and PSF (0%) (p<0.001) (Table 2). Radiographically, compared to those with IFP and SLJS, patients with PSFs had increased mean prepatellar swelling (6.1 and 6.5 versus 12.9mm, p<0.001), intra-articular effusion (6.1 and 4.9 versus 9.2mm, p<0.001), maximum fragment size (26 and 17.7 versus 45.3mm, p<0.001) and maximum fragment displacement (1.24 and 1.45 versus 13.30mm, p<0.003) respectively. Compared to SLJS, PSF and IPF patients had higher patella alta with mean Insall-Salvati ratios > 1.2 (Table 3). Conclusions: Differences in clinical features such as straight leg raise, knee swelling, knee effusion, ability to bear weight and radiographic features such as prepatellar swelling, intra-articular effusion, fragment displacement/size/shape/location can all be helpful in improving the accuracy of diagnosing inferior pole injuries in pediatric patients.

The “Shirt Pocket” Technique—An Alternative for Augmentation-Mastopexy

Augmentation-mastopexy is a frequent procedure with high rates of early recurrence of breast ptosis, mainly after subglandular approach. The dual-plane techniques, based on the cranial dissection of the pectoralis, is the most used, but this plane does not cover the inferior pole of the breast. Then, the possibility of a downward dissection of the muscle seems to be more reasonable to retain the implant and improve postoperative results. This study aimed to review the anatomy of the pectoralis in cadavers and the use of its downward dissection to create a pocket for breast implant as a “shirt pocket.” This maneuver was associated with a superior-based dermoglandular flap to overprotect the inferior pole. No complications were related in the postoperative period. The anatomic review showed that the “shirt pocket” is a safe option if done carefully. The technique demonstrated to be feasible and seemed to be effective, being another alternative to prevent early recurrence of breast ptosis in these procedures.

Suture Anchor Versus Transosseous Tunnel Repair for Inferior Pole Patellar Fractures Treated With Partial Patellectomy and Tendon Advancement: A Biomechanical Study

Background: Comminuted inferior pole patellar fractures can be treated in numerous ways. To date, there have been no studies comparing the biomechanical properties of transosseous tunnels versus suture anchor fixation for partial patellectomy and tendon advancement of inferior pole patellar fractures. Hypothesis: Suture anchor repair will result in less gapping at the repair site. We also hypothesize no difference in load to failure between the groups. Study Design: Controlled laboratory study. Methods: Ten cadaveric knee extensor mechanisms (5 matched pairs; patella and patellar tendon) were used to simulate a fracture of the extra-articular distal pole of the patella. The distal simulated fracture fragment was excised, and the patellar tendon was advanced and repaired with either transosseous bone tunnels through the patella or 2 single-loaded suture anchors preloaded with 1 suture per anchor. Load to failure and elongation from cycles 1 to 250 between 20 and 100 N of force were measured, and modes of failure were recorded. Statistical analysis was performed using a paired 2-tailed Student t test. Results: The suture anchor group had less gapping during cyclic loading as compared with the transosseous tunnel group (mean ± SD, 6.83 ± 2.23 vs 13.30 ± 5.74 mm; P = .047). There was no statistical difference in the load to failure between the groups. The most common mode of failure was at the suture-anchor interface in the suture anchor group (4 of 5) and at the knot proximally on the patella in the transosseous tunnel group (4 of 5). Conclusion: Suture anchors yielded similar strength profiles and less tendon gapping with cyclic loading when compared with transosseous tunnels in the treatment of comminuted distal pole of the patellar fractures managed with partial patellectomy and patellar tendon advancement. Clinical Relevance: Suture anchors may offer robust repair and earlier range of motion in the treatment of fractures of the distal pole of the patella. Clinical randomized controlled trials would help clinicians better understand the difference in repair techniques and confirm the translational efficacy in clinical practice.