Nonmetallic tension band fixation is a viable and low-complication surgical technique in patellar fractures: a five-year retrospective study

BACKGROUND

Traditionally, patellar fractures (PFs) have been managed using metallic tension band fixation, a method often associated with a notable rate of complications. Considering these challenges, this study explores the potential of nonmetallic fixation as a treatment option for PFs. This research aims to provide robust evidence supporting the use of the nonmetallic tension band fixation technique as an effective alternative to conventional metallic tension band fixation, thereby advancing the standard of care in treating these fractures.

METHODS

This retrospective study analyzed a consecutive patient series presenting with PFs from 2008 to 2021, treated with a nonmetallic tension band fixation technique. Inclusion criteria were strictly defined to include individuals over 18 years of age with isolated PFs requiring surgical intervention. The study focused on evaluating postoperative complications and clinical outcomes, as measured by standardized scoring systems, at the final follow-up point to assess the efficacy and safety of the employed surgical technique.

RESULTS

In this study, with a mean follow-up of 64 ± 7 months, a total of 64 patients who received open reduction and internal fixation (ORIF) for PFs were enrolled. Among these, five cases required additional surgical interventions. Specifically, two cases were due to knee stiffness, while the remaining three involved complications such as superficial infection, skin irritation, or delayed wound healing. The mean postoperative values recorded for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Oxford knee score (OKS), and visual analog scale (VAS) were 20.4 ± 2.3, 35.5 ± 5.3, and 1.6 ± 0.4, respectively. There were no complications related to the nonmetallic fixation technique or instances of loss of reduction.

CONCLUSION

This study substantiates that nonmetallic tension band fixation is a safe and effective alternative to traditional metallic tension band fixation for patellar fractures. The study's low-complication rate and reoperation frequency underscore the value of nonmetallic implants in mitigating adverse effects and enhancing clinical outcomes.

LEVEL OF EVIDENCE

IV.

Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study

BACKGROUND

The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja.

METHODS

We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja.

RESULTS

Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03-4.33, p = 0.042).

CONCLUSION

In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.

A New Method of Krackow Suture Combined with Nice Knot for the Treatment of Inferior Patellar Fractures

Introduction

We present a new surgical technique of Krackow suture combined with vertical Nice knot for the treatment of inferior patellar fractures and report the clinical results.

Patients and Methods

Seventeen consecutive patients admitted with inferior patellar fractures over a 2-year period from June 2019 to February 2022 were prospectively enrolled. The AO classification was 34-A1. All patients underwent open reduction and fixation with Krackow sutures in combination with vertical Nice knot. Postoperative follow-up was performed for at least 1 year to evaluate knee function.

Results

The mean age of seventeen patients was 53.2 ± 9.5 years (39-68 years), and all patients were followed up for more than 12 months. The operation time was 54.6 ± 7.7 min (42-68 min). No patients had nonunion, joint stiffness, and joint pain. All cases achieved bony union at an average of 9.9 ± 1.5 weeks (8-13 weeks) after surgery. At the last follow-up, there was no significant difference in range of motion between the injured knee (129.7 ± 3.3°, range 125-135°) and the unaffected knee (130.8 ± 3.8°, range 126-137°) (t = 0.28, P > 0.05). The mean Bostman score of the knee joint was 29.6 ± 0.7, including 15 excellent cases (88.2%) and two good case (11.8%).

Conclusion

Krackow sutures combined with vertical Nice knots are stable and reliable in the treatment of inferior patellar fractures. Knee rehabilitation can be performed immediately after surgery and satisfactory knee function can be achieved. It is a safe, simple, and reliable alternative surgical method, and patients do not need to bear the secondary surgical injury of removing the internal fixation material. Therefore, it is suitable for the application of clinical promotion.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-023-01093-0.

Do we need to restore patellar thickness after total knee arthroplasty with patellar resurfacing?

PURPOSE

The aim of this study was to investigate whether increased patellar thickness after resurfacing decreased knee flexion angle and had any effect on functional outcomes comparing with patellar thickness restoration (patelloplasty) in patients undergoing primary total knee arthroplasty (TKA) or not.

METHODS

We retrospectively reviewed 220 patients undergoing primary TKA: 110 patients undergoing patelloplasty and 110 patients received overstuffed patellar resurfacing using subchondral bone cut at lateral facet technique were recruited. The mean increase in patellar thickness after resurfacing equal to 2 ± 1.2 mm. The outcomes were postoperative knee flexion angle and modified Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score at minimum 2 year after surgery.

RESULTS

The mean postoperative knee flexion angles were similar between overstuffed resurfacing group and patelloplasty group (132 ± 7° vs. 134 ± 8°, 95% confidence interval [CI] - 6.9-1.8°, p = 0.1). The mean increase in postoperative knee flexion was 13° in both groups (p = 0.94). The mean change of overall modified WOMAC score was also similar between the two groups (42 ± 12 vs. 39 ± 9 points, 95% CI - 1.7-9.4 points, p = 0.17).

CONCLUSION

This study demonstrated that increased patellar thickness has no effect on postoperative knee flexion angle and functional outcomes in TKA. The finding clarified the misunderstanding principle of native patellar thickness restoration after resurfacing which had made many surgeons to refrain from resurfacing especially in patient who had thin patella.

Skyline view of the patella does not increase fracture detection: A non-inferiority diagnostic study

PURPOSE

Patella fractures are frequent injuries in the adult population. Initial study is made by plain radiographs and the standard set includes the skyline view of patella. Recommendation for use of this projection is variable among the experts, without data that support its performance in the diagnosis of patella fractures. The main purpose of this study was to determine the sensitivity of the antero-posterior and lateral view of the knee, without skyline view, in the diagnosis of patella fracture.

METHODS

A retrospective non-inferiority diagnostic study was designed with all the knee trauma adult patients of an Emergency Department in a single center in five years. A random sample of all the consecutive patella fracture cases were taken to elaborate the case group. The control group was matched by sex and age. Two blinded orthopedic surgeons reviewed the cases and control radiographs and defined the presence of fracture, with or without skyline view, with a wash-out time of three weeks between the two evaluations. Non-inferiority was defined a priori at 90% of minimum sensitivity.

RESULTS

140 patients were evaluated (70 cases and 70 controls). Sensitivity of the set without skyline view was 92.86% (CI 95% 0.90 - 0.96) and the standard set was 97.86% (CI 95% 0.96 - 0.99), without significant differences (p = 0.1) CONCLUSION: Sensitivity of the plain radiograph set without skyline view is non-inferior to the standard set. The routine use of skyline view when suspecting patella fractures is questionable.

A novel technique of a new cannulated screw for treatment of inferior pole patellar fractures: a finite element study

OBJECTIVE

We invented a new cannulated screw with holes on the tail, which called Ding's screw. The goal of this study was to evaluate the biomechanical outcomes of this new screw with tension band wiring for the treatment of inferior pole patellar fractures in a finite element model.

METHODS

We conducted a finite element biomechanical study using two fixation methods: Ding's screw and tension band wiring (DSTBW) and cannulated screws and tension band wiring (CSTBW). Two methods were simulated to fix the inferior pole patellar fracture in a finite element model. The relative displacement and stress distribution were analyzed and compared.

RESULT

There were less displacement and stress distribution of DSTBW in different knee movement (30°, 60°, 90°, 120°) when compared to CSTBW. The highest value of displacement of the fracture and von Mises stress of the internal fixation happened in 120° knee movement in both groups. The highest displacement of the DSTBW was less than that of the CSTBW (1.92 mm to 2.12 mm). The highest value of the stress on the screws was 110.60 MPa in DSTBW group, and 132.90 MPa in CSTBW group. The highest value of the stress on the titanium cable was 38.51 MPa in DSTBW group, and 41.91 MPa in CSTBW group.

CONCLUSION

DSTBW fixation provides more stability than CSTBW fixation model in a finite element study.

Osteosynthesis of a patellar fracture with repair of the knee extensor mechanism: Case report

Patella fractures correspond to 1 % of all fractures. In recent decades, the role of the patella in increasing the lever arm of the quadriceps has been well defined. Surgical treatment is indicated for open fractures, those that compromise the function of the extensor mechanism, those with a joint gap >5 mm and/or joint incongruity >3 mm, a group that corresponds to around 30 % of the total. Anatomical reduction and stabilization with various types of modified tension bands is the most frequently used procedure. Biomechanical studies have shown that stabilization through the use of a tension band replacing the Kirchner wires with cannulated screws presents adequate resistance to fracture displacement and provides greater stability than the classic configuration, maintaining the theoretical principle of converting the forces of anterior tension of the patella generated by the quadriceps in compression at the level of the articular surface. A case of a patient who required reduction and osteosynthesis of an exposed patella fracture, associated with an extensor mechanism lesion, is presented. Clinical and radiographic characteristics of the patient and the resolution of the case are described.

Surgical treatment of inferior pole fractures of the patella: a systematic review

PURPOSE

This study aimed to comprehensively review the existing evidence concerning surgical treatment of inferior pole fractures of the patella and to report the outcomes and complications of different fixation techniques.

METHOD

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches of PubMed, Scopus, and Web of Science were conducted in March 2023. Studies were screened against predecided inclusion and exclusion criteria. The extracted data included fracture characteristics, surgical techniques, and radiographic and functional outcomes. The Methodological Index for Non-Randomized Studies (MINORS) quality assessment tool was used to assess the eligible literature. The primary outcome was postoperative range of motion of different surgical methods, and the secondary outcomes were other clinical results and complications.

RESULTS

A total of 42 studies satisfied all the inclusion criteria and were deemed suitable for review. Fourteen case-control studies and 28 case series were selected, for a total of 1382 patients with a mean age of 51.0 years (range = 11-90). The follow-up period ranged from 6 to 300 months. The surgical techniques were categorized based on the device used as follows: (1) rigid fixation device; (2) tensile fixation device; (3) mixed device; and (4) extra-patella device.

CONCLUSION

Regarding the outcomes following surgical treatment of inferior pole fractures of the patella, the postoperative range of motion (ROM) of each technique ranged from 120° to 135°, with the exception of that involving the patellotibial wire which had poorer outcomes. The lowest functional score was also found in those using the patellotibial wire. Complications after surgery are rare, but approximately half of the patients required additional surgery for implant removal, particularly those whose initial surgery involved rigid fixation devices. It's worth noting that bony fragment excision is no longer recommended, and the combined use of multiple surgical devices is now more common.

A novel patella fracture fixation technique: finite element analysis

INTRODUCTION

Patella fractures account for approximately 1% of all bone fractures. The tension band wiring technique has been used in surgical treatment. However, there is no clear information about the location of the K-wires in sagittal plane. Thus, a transverse fracture line was created in the patella finite element model and fixed with Kirchner (k) wires and cerclage at different angles and compared with two different standard tension band models.

MATERIALS AND METHODS

A total of 10 finite element models were created to study AO/OTA 34-C1 patella fractures. Two models used the classical tension band method with either circumferential or 8-shaped cerclage wire. The other 8 models used K-wires placed at 45° or 60°, either alone or combination with cerclage wire. A force of 200 N, 400 N, and 800 N were applied at 45° knee angle and the resulting data fracture line opening, surface pressure and stress in the implants were analyzed through finite element analysis.

RESULTS

When all the results are considered, it was determined that the K-wires 60° crossing at the fracture line and with cerclage modeling was superior to the other models. The diagonal placement of the K-wires with cerclage (could be 45° or 60° medium) was superior to the reference models.

CONCLUSIONS

This study has shown that the new fixation method we propose could come to the fore as an alternative method to be used successfully in transverse patella fractures and lower complications. In transverse patellar fractures, the use of K-wires crossed at 60° may be a good alternative to the standard method.

The effect of Ding's screws and tension band wiring for treatment of inferior pole patellar fractures

OBJECTIVES

We developed a cannulated screw with holes in the tail, named the Ding's screw. The objective of this study was to evaluate the clinical effect of Ding's screw in the treatment of inferior pole patellar fracture.

METHODS

From March 2017 to October 2021, 68 patients with inferior pole patellar fracture in our department were retrospectively reviewed. According to different treatment methods, they were divided into Ding's screw and tension band wiring group (DSTBW) and cannulated screws and tension band wiring group (CSTBW). Radiological and clinical outcomes were evaluated and compared.

RESULTS

There were 33 cases in DSTBW group and 35 cases in CSTBW group. The mean follow-up duration was 14.5 ± 2.6 months in the DSTBW group and 15.0 ± 2.3 months in the CSTBW group. No significant differences in age, sex, operative side or time to surgery were present between the two groups. Skin breakdown and infection were not significantly different among the groups (P > 0.05). At the last follow-up, the average Bostman score of the DSTBW group was 28.5 ± 1.3(excellent) and that of the CSTBW group was 27.8 ± 1.6(good), with statistical significance (P = 0.045). The average Lysholm score of the DSTBW group was 94.1 ± 3.4 (good), and that of the CSTBW group was 90.1 ± 4.4 (good), and the difference was statistically significant (P < 0.001). The average knee joint ROM of the DSTBW group was 135.6 ± 6.8˚, and that of the CSTBW group was 130.1 ± 6.7˚, and the difference between the two groups was statistically significant (P = 0.001).

CONCLUSIONS

DSTBW is an effective method for the treatment of inferior pole patellar fractures with stable fixation and good functional effect.

A modified separate vertical fixation by wires and titanium cables for comminuted inferior patella fracture: A technique note and finite element analysis

PURPOSE

Comminuted inferior patellar pole fractures are challenging injuries and require adequate treatment due to the extension mechanism of the knee.

METHODS

A modified separate vertical fixation by wires and Titanium cables was established according to a finite element biomechanical study. Between September 2018 and May 2021, 18 patients with inferior pole fractures of the patella were retrospectively enrolled in this study.

RESULTS

The results of the finite element analysis showed the concentration of stress in the intermediate vertical wire and the cerclage wire. As a partial replacement for steel wires, Titanium cables provide less concentration of stress on the vertical wire (489.4 MPa vs 441.2 Mpa) and less cutting force on the bone (75.87 Mpa vs 53.27), which reduces the possibility of internal fixation failure and improves the stability of internal fixation. In the clinic study, No patients experienced non-union of the fracture, loss of fracture repositioning, malunion of wounds, or wire breakage. At the last follow-up, the average range of motion was 134.7°±11.2°, and the Lysholm Score was 90.7 ± 3.9.

CONCLUSIONS

The separate vertical fixation by wires and titanium cables is an effective fixation method for treating displaced, comminuted inferior pole fractures, which attributes to early exercise and better function.

Observation of the effect of arthroscopically assisted percutaneous minimally invasive Kirschner wire tension band fixation on the treatment of patellar fractures

BACKGROUND

Patellar fractures are common intra-articular fractures. Arthroscopically assisted reduction and fixation has been shown to advantageous in the treatment of patellar fractures.

OBJECTIVE

This study aimed to investigate the effect of arthroscopically assisted percutaneous minimally invasive Kirschner wire tension band fixation on the treatment of patellar fractures.

METHODS

Thirty-four patients with acute closed patellar fractures enrolled in the study and were managed by arthroscopically assisted percutaneous minimally invasive Kirschner wire tension band fixation under epidural anesthesia. Among these patients, 24 were males, and ten were females. The mean age of these patients was 38 ± 0.8 years (range: 25-62 years). Of these patients, 20 had transverse fractures, five had longitudinal fractures, four had marginal oblique fractures, and five had multifragmentary upper and lower pole. Fracture causes: 25 were caused by falls, and nine were caused by traffic accidents. The time from injury to operation was 6-48 hours, with an average of 23 hours. The average post-operative follow-up was 12.8 months, and at the end of follow-up, the Boestman scoring system was used to evaluate knee joint function.

RESULTS

All the wounds healed by first intention, and no infections, skin necrosis, joint stiffness, or other complications occurred. Three months after operation, the tension band wire had broken in one patient, but the fracture had united, and this did not affect the prognosis. In eight patients, the average circumference at 10 cm above the patella was 0.6 cm less on the injured side than on the contralateral side. The average Boestman score was 27.5. The final result was excellent in 25 patients, good in eight patients, and acceptable in one patient.

CONCLUSION

Arthroscopic management of simple patellar fracture with percutaneous minimally invasive Kirschner wire tension band fixation is less invasive than open operation, while still leading to firm fixation, and is conducive to early functional training and functional recovery, and thus is an effective method of management for patellar fractures.

Biomechanical comparison of different screw-included angles in crossing screw fixation for transverse patellar fracture in level walking: a quasi-dynamic finite element study

BACKGROUND

A minimally invasive technique with various screw configurations without open surgery is currently used for the fixation of transverse patellar fractures. Percutaneous crossing screw configuration has been reported to have a good bone union rate in patellar fractures. However, the difference in mechanical stability of the fractured patella between different screw-included angles has not been fully investigated. Hence, this study aims to compare the mechanical stability of parallel and crossing screw fixations with different screw-included angles for the fixation of transverse patellar fractures during level walking.

METHODS

A finite element knee model containing a patella with a transverse fracture is created. Two headless compression screws with different angles (0°, 30°, 60°, and 90°) are used to fix the fracture. The loading conditions of the knee joint during level walking are used to compare the stability of the fractured patella with different fixation screw configurations.

RESULTS

The results indicate that the maximum fracture gap opening distance increased with an increase in the included angle. Two parallel screws yield the smallest gap distance among all screw configurations. The maximum gap opening distances at the anterior leading edge of the fractured patella with two parallel screws and two screws having an included angle of 90° are 0.73 mm and 1.31 mm, respectively, at 15% walking cycle.

CONCLUSIONS

Based on these results, the superior performance of two parallel screws over crossing screw fixations in the fixation of transverse patellar fractures is established. Furthermore, the smaller the angle between the crossing screws, the better is the stability of the fractured patella.

Management of comminuted inferior patellar pole fractures with cerclage-wire-augmented separate vertical wiring: a retrospective clinical study

PURPOSE

Comminuted inferior patellar pole fractures are challenging injuries and require effective treatment due to the extension mechanism of the knee. This study aims to evaluate the outcome of above fractures treated with a modified technique of cerclage-wire-augmented separate vertical wiring (SVW) with cerclage wiring passed through the proximal patella.

METHODS

Retrospective analysis (1/2017-1/2020) were performed for patients that were treated with three SVWs through the posterior margin of proximal fragment and directly to the anterosuperior border of patella, combined with a cerclage wiring passed through the proximal patella. Patients who experienced comminuted inferior patellar pole fractures within 3 weeks were included, and the outcome was evaluated radiologically and clinically by Bostman score after a minimum of 12 months following surgery. Further evaluation included the operation time and complication rate.

RESULTS

A total of 20 patients (10 males, 10 females) with a mean age of 54 ± 14.5 years (26-83 years) and a follow-up of 18.9 ± 6.6 months (12-36 months) were evaluated. The average operation time was 45.7 ± 8.8 min (30-60 min). At final follow-up, the average range of motion was 131.3° ± 3.5° (125°-135°), and the mean Bostman score was 29.4 ± 0.7 points (28-30) and graded excellent in all cases. Two patients experienced occasional giving way of the knee. Radiologically no loss of reduction, implant breakage, nonunion or skin irritation was observed.

CONCLUSIONS

The cerclage-wire-augmented SVW with cerclage wiring passed through the proximal patella appears to be a safe and simple technique which can effectively treat the comminuted inferior patellar pole fractures.

No difference in clinical and radiological outcomes following fixation of transverse patella fractures with either suture tape or metallic cerclage: A retrospective comparative study

INTRODUCTION

Several surgical techniques have been proposed for the treatment of patellar fractures. The aim of this study is to compare the clinical efficacy and complication rates of treatment using suture tape circumferential cerclage (STCC) and metallic wire circumferential cerclage (MWCC) for the surgical treatment of displaced transverse patellar fractures (TPFs).

HYPOTHESIS

The hypothesis is that the use of the suture tape would be associated with a significantly lower rate of re-operation than metallic cerclage but no differences in other clinical outcomes.

PATIENTS AND METHODS

A retrospective comparative analysis of the clinical outcomes of consecutive patients undergoing fixation of TPFs with either MWCC or STCC between January 2017 and December 2018 was undertaken. All patients underwent evaluation with standardised radiographs at one, three, and six months after surgery to determine rates of union, non-union, loss of fixation and malunion. All patients underwent a final clinical evaluation at 18 months postoperatively to evaluate clinical scores and complications.

RESULTS

A total of 26 patients were included in the study. Thirteen patients underwent STCC and 13 underwent MWCC. There were no complications in the STCC group. In the MWCC group, one patient underwent hardware removal at 2 months postoperatively due to painful prominence. There was no significant difference in re-operation rates between the STCC and MWCC groups (p=1). There were no cases of non-union, malunion or loss of fixation throughout the series. At the final clinical follow-up of 18months, there were no significant differences in KSS, KOOS or Böstman scores between the groups.

CONCLUSION

No significant differences were identified when comparing the clinical outcomes of fixation of AO/OTA 34C1/2 fractures with suture tape or metallic cerclage fixation concerning re-operation rates, union rates, loss of fixation and functional outcome measures. These results cannot be extrapolated to more complex injury patterns or surgical techniques in which prominence of implanted material is more likely.

LEVEL OF EVIDENCE

III.

Patellar Tendon Reconstruction Using Autologous Hamstring Tendons for the Treatment of Extensive Patellar Tendon Ossification

Background

Extensive patellar tendon ossification is very uncommon and requires surgical intervention when ossification significantly affects knee function. While various approaches and grafts are available for reconstructing ruptured patellar tendons, there is a paucity of literature regarding the management of joint ankylosis due to severely ossified patellar tendons.

Case Presentation

This is a case involving an extensively ossified patellar tendon after patellar and tibial tuberosity fracture fixation. Reconstruction of the patellar tendon was performed using ipsilateral semitendinosus and gracilis autografts. At the latest follow‐up of 12 months, the patient achieved knee flexion up to 120° with a slight extension lag and resumed daily activities.

Conclusions

Autograft hamstring reconstruction of the patellar tendon is suitable for extensive heterotopic ossification of the patellar tendon, resulting in significant improvement in postoperative knee function. Similar patients may be referred for this reconstruction technique.

Preoperative incidence and risk factors of deep vein thrombosis in patients with an isolated patellar fracture

Purpose

This study aimed to investigate the incidence, location, and related factors of preoperative deep venous thrombosis (DVT) in patients with isolated patellar fractures.

Methods

Patients with an isolated patellar fracture, admitted between January 2013 and December 2019 at our institution, were retrospectively analyzed. Upon admission, patients underwent routine Doppler ultrasound scanning (DUS) of the bilateral lower extremities to detect DVT; those with DVT were assigned to the case group and those without DVT to the control group. Patients in both groups did not perform preoperative off-bed weight-bearing exercises. Data on demographics, comorbidities, and laboratory test results upon admission were extracted. Variables were evaluated between the two groups using univariate analyses, and independent risk factors associated with DVT were identified by logistic regression analysis.

Results

During the study period, 827 patients were included, of whom 5.8% (48/827) were found to have preoperative DVT. In DVT patients, 85.4%(41/48) were injured, 8.3%(4/48) were not injured, and 6.3%(3/48) were lower limbs. Multivariate analysis showed that male (male vs. female, odds ratio, OR = 2.25), delayed from injury to DUS (in each day, OR = 1.29), and elevated plasma D-dimer level (> 0.5 µg/mL, OR = 2.47) were independent risk factors associated with DVT.

Conclusions

Despite the low prevalence of DVT after an isolated patellar fracture, this study underscores the importance of identifying those with a high risk of DVT, especially those with multiple identifiable factors, and encourage the early targeted use of anti-thromboembolic agents to reduce DVT occurrence.

Autogenous iliotibial band enhancement combined with tendon lengthening plasty to treat patella baja: A case report

BACKGROUND

Patella baja is a severe complication after knee injury or surgery, resulting in pain and impaired movement. This disorder is also a substantial challenge for orthopaedic surgeons. Currently, no consensus exists regarding the gold standard management of patella baja. If not appropriately treated, significant dysfunction of the knee joint will occur.

CASE SUMMARY

A 46-year-old man with a left patellar fracture was treated with tension band fixation at a local hospital. He had undergone a second operation at the same hospital because of limited knee flexion 6 mo after surgery. Unfortunately, the patellar tendon was ruptured. The patellar tendon was subsequently repaired using an ipsilateral semitendinosus tendon. Two years later, the patient presented to our department with knee pain and loss of range of motion. Autogenous iliotibial band (ITB) enhancement combined with sagittal tendon lengthening plasty was used to improve the symptoms of the knee joint. The patient was followed up for 2 years. The knee joint function of the patient returned to the normal level.

CONCLUSION

We successfully treated patella baja using autogenous ITB enhancement combined with sagittal tendon lengthening plasty.

Triangular configuration with headless compression screws in the fixation of transverse patellar fracture

A triangular configuration with three parallel cannulated screws is an established treatment for fixing transverse patellar fractures; however, the stability achieved with this approach is slightly lower than that attained with cannulated screws combined with anterior wiring. In the present study, triangular configurations were modified by partially or totally replacing the cannulated screws with headless compression screws (HCSs). Through finite element simulation involving a model of distal femoral, patellar, and proximal tibial fractures, the mechanical stability levels of the modified triangular configurations were compared with that of two cannulated screws combined with anterior wiring. Four triangular screw configurations were developed: three HCSs in a forward and backward triangular configuration, two deep cannulated screws along with one superficial HCS, and two superficial cannulated screws with one deep HCS. Also considered were two parallel cannulated screws (inserted superficially or deeply) combined with anterior wiring. The six approaches were all examined in full knee extension and 45° flexion under physiological loading. The highest stability was obtained with the three HCSs in a backward triangular configuration, as indicated by the least fragment displacement and the smallest fracture gap size. In extension and flexion, this size was smaller than that observed under the use of two deeply placed parallel cannulated screws with anterior wiring by 50.3% (1.53 vs. 0.76 mm) and 43.2% (1.48 vs. 0.84 mm), respectively. Thus, the use of three HCSs in a backward triangular configuration is recommended for the fixation of transverse patellar fractures, especially without the use of anterior wiring.

Plate osteosynthesis in patellar fractures: a systematic review and meta-analysis

INTRODUCTION

To perform a systematic review and assess the indications, outcomes, complications, and union rates associated with plate osteosynthesis in patellar fractures compared to tension band wiring.

METHODS

The systematic search was conducted for articles in PubMed, Embase Biomedical, Cochrane central, and LILACS databases (date of inception to July 30, 2020). Articles were included if they were randomized control trials, cohort studies, case-control studies, and case series (with more than five cases), which focused on the clinical outcomes of patients with plate osteosynthesis as a treatment for fracture of the patella and had a minimum follow-up of 3 months. All studies were assessed according to their level of evidence, the number of patients, age of patients, fracture patterns described, complications of treatment, and results summarized. Meta-analysis could only be done for two parameters (complications and reoperations) due to the paucity of data and heterogeneity of studies' limited statistical analysis. The data are presented as a review table with the key points summarized.

RESULTS

Twenty studies (seven prospective and 13 retrospective articles) identified 533 patients with 534 fractures who had undergone plate osteosynthesis for fracture of the patella. The most common fracture treated with plate osteosynthesis was 34C.

CONCLUSION

Basket plate was most commonly used for inferior pole fractures, while mesh plates were for intra-articular patella fractures. Overall plating was associated with better clinical outcomes, fewer complication rates, and high union rates compared to tension band wiring for patella fractures.

A case report of patellar fracture treated by percutaneous strong suture technique

Tension-band wiring with metal such as Kirshner wire or soft steel wire is commonly used for the treatment of patellar fractures. In recent years, metal-free surgery using a strong suture with high breaking strength has been reported to have excellent outcomes. We report a case of patellar fracture treated with a minimally invasive percutaneous strong suture. The patient is a 57-year-old salesman who fell at work, hit his knee, and came to our hospital complaining of pain. His range of motion was −15° in extension and 60° in flexion. His X-ray results showed a transverse fracture of the right patella with a 3-mm displacement, and surgery was performed 7 days post-injury. A small incision of 1 cm was made distally and proximally on the patella. Two 2.0-mm perforated K-wires were inserted from distal to proximal sides, and the wire was pulled out proximally with FiberWire® No. 2. The distal end of the FiberWire was pulled through the proximal incision via the anterior surface of the patella and finally fastened. The procedure was completed in 21 min. The patient did not use a brace since the operation day and was not restricted in terms of load or range of motion. He was able to walk without any assistance after 10 days and returned to driving and office work 14 days postoperatively. At the final follow-up, no symptoms of skin irritation were detected, and the patient did not require suture removal.

•

Patella fractures are operated with strong sutures such as fiberwire.

•

Strong suture technique has the same or higher strength as soft steel wire tension band.

•

Less complications such as subcutaneous pain due to the non-metal method.

•

Strong suture technique can be performed percutaneously.

•

Strong suture technique is minimally invasive surgery for patellar fractures.

[Comparative study on the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures]

Objective

To compare the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures.

Methods

Between January 2017 and January 2019, 26 patients with type C patellar fractures were treated with improved Kirschner wire tension band fixation (group A), and 24 patients were treated with traditional Kirschner wire tension band fixation (group B). There was no significant difference in gender, age, injury cause, disease duration, and side and type of fracture between 2 groups ( P>0.05). The operation time, intraoperative blood loss, the visual analogue scale (VAS) scores at 1 and 3 days after operation, the fracture healing time, and the occurrence of complications (skin irritation of Kirschner wires, failure of internal fixation, fracture reduction loss) were recorded, and the knee function was evaluated by Lysholm scoring standard in 2 groups.

Results

The operation time in group A was significantly less than that in group B ( t=-4.742, P=0.000). There was no significant difference in the intraoperative blood loss and VAS scores at 1 and 3 days after operation between 2 groups ( P>0.05). All incisions healed by first intention. All patients were followed up 8-15 months, with an average of 11 months. The fracture healing time was (3.3±0.6) months in group A and (3.2±0.6) months in group B, showing no significant difference ( t=0.589, P=0.559). At last follow-up, the knee joint function was evaluated according to Lysholm scoring standard. And there were 15 cases of excellent, 8 cases of good, and 3 cases of fair, with an excellent and good rate of 88.5% in group A; there were 8 cases of excellent, 7 cases of good, 7 cases of fair, and 2 cases of poor, with an excellent and good rate was 62.5%. The difference between 2 groups was significant ( Z=2.828, P=0.005). The internal fixators were removed after the fracture healed in 2 groups. At last follow-up, no skin irritation of Kirschner wires occurred in group A, but 3 cases in group B. X-ray films reexamination showed that 5 cases of internal fixation failure and no fracture reduction loss were found in group A, while 9 cases of internal fixation failure and 1 case of fracture reduction loss in group B. The incidence of complications in group A was 19.2% (5/26), which was significantly lower than that in group B (54.2%, 13/24) ( χ ²=6.611, P=0.010).

Conclusion

Compared with the traditional Kirschner wire tension band fixation, the improved Kirschner wire tension band fixation in treatment of type C patellar fracture can shorten the operation time, reduce the incidence of complications, and benefit the functional recovery of knee joint.

[Progress in the surgical treatment of the patellar fracture]

OBJECTIVE

To review research progress of surgical treatment of patellar fractures.

METHODS

The domestic and foreign literature about patellar fracture treatment in recent years was extensively consulted, and the advantages, disadvantages, and indications of various surgical treatments were summarized.

RESULTS

The patella plays an important role in knee flexion and extension activities, and the fracture significantly affects the patient's quality of life. At present, the surgical methods include open reduction and internal fixation and patella resection. The internal fixation methods include ring/binding patella fixation, tension band wiring and improved technology, tension band wiring combined with other methods, screw fixation (including absorbable screws), steel plate fixation, and patella fixator fixation. Each surgical method has different indications, advantages, and disadvantages. Choosing an appropriate treatment plan plays a crucial role in clinical prognosis.

CONCLUSION

There are many surgical treatments for patellar fractures. In order to improve the effectiveness and reduce postoperative complications, it is necessary to choose the most appropriate treatment strategy for the type of fracture.

Fracture of the inferior pole of the patella: tension band wiring versus transosseous reattachment

BACKGROUND

The optimal surgical technique for the fixation of inferior pole patellar fracture remains controversial. The aims of this study were (1) to compare clinical and radiological outcomes following fixation of inferior pole patellar fracture by using tension band wire (TBW) and transosseous reattachment (TOR) without excision of the bony fragment and (2) to determine the risk factors for postoperative radiological loss of reduction.

METHODS

For this retrospective cohort study, consecutive patients with inferior pole patellar fracture between January 2010 and December 2017 were recruited. The patients were grouped according to their fixation method (TBW or TOR), and demographic data, clinical outcomes, and postoperative Insall-Salvati (IS) ratio were analyzed. Then, the patients were grouped according to radiological loss of reduction, the possible risk factors for loss of reduction were identified, and odds ratios were calculated.

RESULT

This study included 55 patients with inferior pole patellar fracture; 30 patients were treated using TBW and 25 were treated using TOR. Clinical failure occurred in two patients in the TBW group (7%) and three in the TOR group (12%). The rate of radiological loss of reduction was significant higher in the TOR group, whereas removal of implants was significantly more common in the TBW group. Patella baja was noted immediately after surgery in the TOR group, but the IS ratios of the two groups were similar after 3 months. Fracture displacement of more than 30 mm was the only independent risk factor for postoperative radiological loss of reduction.

CONCLUSION

For treating inferior pole patellar fracture, both TWB and TOR were effective and had a low clinical failure rate. In 60% of patients undergoing TBW fixation, however, additional surgery was required to remove the implants. Patella baja occurred immediately following TOR, but the patellar height was similar to that in the TBW group after 3 months. Surgeons should be aware of the high risk of postoperative radiological loss of reduction, especially when the fracture displacement is more than 30 mm.

Internal fixation and unicompartmental knee arthroplasty for an elderly patient with patellar fracture and anteromedial osteoarthritis: A case report

BACKGROUND

Open reduction and internal fixation (ORIF) is the traditional surgical treatment for patellar fractures, and unicompartmental knee arthroplasty (UKA), especially Oxford UKA, has been increasingly used in patients with medial knee osteoarthritis (OA). However, the process of choosing treatment for patients with both patellar fractures and anteromedial knee OA remains unclear. We present the case of a patient with a patellar fracture and anteromedial OA.

CASE SUMMARY

We present the case of a 72-year-old woman with a history of bilateral medial compartment OA of the knees and a right Oxford UKA. She also experienced a recent left patellar fracture. ORIF and Oxford UKA were performed in a single stage. The patient showed excellent postoperative clinical results.

CONCLUSION

ORIF and Oxford UKA can be performed simultaneously for patients with patellar fracture and anteromedial OA on the same knee.

Biodegradable magnesium pins enhanced the healing of transverse patellar fracture in rabbits

Displaced fractures of patella often require open reduction surgery and internal fixation to restore the extensor continuity and articular congruity. Fracture fixation with biodegradable magnesium (Mg) pins enhanced fracture healing. We hypothesized that fixation with Mg pins and their degradation over time would enhance healing of patellar fracture radiologically, mechanically, and histologically. Transverse patellar fracture surgery was performed on thirty-two 18-weeks old female New Zealand White Rabbits. The fracture was fixed with a pin made of stainless steel or pure Mg, and a figure-of-eight stainless steel band wire. Samples were harvested at week 8 or 12, and assessed with microCT, tensile testing, microindentation, and histology. Microarchitectural analysis showed that Mg group showed 12% higher in the ratio of bone volume to tissue volume at week 8, and 38.4% higher of bone volume at week 12. Tensile testing showed that the failure load and stiffness of Mg group were 66.9% and 104% higher than the control group at week 8, respectively. At week 12, Mg group was 60.8% higher in ultimate strength than the control group. Microindentation showed that, compared to the Control group, Mg group showed 49.9% higher Vickers hardness and 31% higher elastic modulus at week 8 and 12, respectively. At week 12, the new bone of Mg group remodelled to laminar bone, but those of the control group remained woven bone-like. Fixation of transverse patellar fracture with Mg pins and its degradation enhanced new bone formation and mechanical properties of the repaired patella compared to the Control group.

•

Kirschner wires (K-wire) with tension band wire is widely used fixation implants for repairing of displaced patellar fractures.

•

Fixation of patellar fracture with Mg pins enhanced new bone formation and mechanical properties of the repaired patella.

•

With a stainless steel tension band wire, Mg pins may be an alternative to K-wire for fixation of patellar fractures.

Chronic paronychia in cats with patellar fracture and dental anomaly syndrome

CASE SERIES SUMMARY

The aim of this case series was to describe the clinical features and treatment of paronychia in cats diagnosed with patellar fracture and dental anomaly syndrome (PADS). Clinical records, photographs, microbiology, cytology and histopathology reports were collected, and follow-up was obtained. Five cats with paronychia were included. All five cats had multiple digits of multiple limbs affected and eventually underwent amputation of the third phalanx of one or multiple digits. A total of 36 digits were affected, 17% (n = 6/36) resolved with medical management and 83% (n = 30/36) were eventually treated successfully by amputation. The cats had treatment with numerous courses of antibiotics (range 7-20; mean 11 courses) over periods of time ranging from 10 to 67 months (mean 32 months).

RELEVANCE AND NOVEL INFORMATION

Chronic paronychia may be an additional clinical feature of PADS and the probable mechanism involves poor integrity of osteopetrotic bone, loss of normal nailbed anatomy and secondary osteomyelitis of the distal phalanx. Medical management with antibiotics, anti-inflammatory therapy and steroid treatment may improve the clinical signs in the short term; however, in severe instances, amputation of the third phalanx of the affected digit seems to be necessary to resolve repeated recurrences and discomfort. Additional information on the long-term outcome is required. In any cat with atraumatic patellar fractures and/or retained deciduous teeth, paronychia may require surgical management if medical management is unsuccessful.

A cadaveric study of the location and morphology of the central patellar ridge for bone-patellar tendon-bone graft

Introduction

The central ridge of the patella is the thickest area of patella and varies among patients. This cadaveric study identified the location and thickness of the bone at the central patella ridge for bone-patellar tendon-bone (BPTB) harvesting.

Materials and methods

Fifty cadaveric knees were assessed. First, the morphology, length, width, and location of the central patellar ridge were recorded. Then, we transversely cut the patella 25 mm from the lower pole and measured the thickness of the anterior cortex, cancellous bone, and cartilage from both the mid-patella and the central ridge location. Finally, the depth of the remaining cancellous bone at the mid-patella was compared to the bone at the central ridge.

Results

The location of the central-patellar ridge deviated medially from the mid-patella in 46 samples with an average distance of 4.36 ± 1 mm. Only 4 samples deviated laterally. The mean patella length was 41.19 ± 4.73 mm, and the width was 42.8 ± 5.25 mm. After a transverse cut, the remaining cancellous bone was significantly thicker at the central ridge compared to the bone at the mid-patella.

Conclusions

Most of the central patellar ridge deviated medially, approximately 4 mm from the mid-patella. Harvesting the graft from the central ridge would have more remaining bone compared to the mid-patella.

Treatment of pelvic fractures in cats with patellar fracture and dental anomaly syndrome

Objectives

The aim of this study was to describe the treatment and outcome of acetabular and other pelvic fractures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice.

Methods

Data were collated on cats with PADS that were reported to have sustained pelvic fractures or had fractures or fissures of the pelvis identified on submitted radiographs. The details of the fractures were recorded, in addition to any treatment and outcome information.

Results

Of the 215 cases reported with PADS, 58 cats (27%) were found to have pelvic fractures, none of which were known to have resulted from significant trauma. There were 101 fractures in total and of these 15 were treated with surgery, including 10 acetabular fractures, two ilial, two pubic and one ischial fracture. Screw loosening and loss of fracture reduction was seen in four of the surgically treated fractures (two pubic fractures, one ilial and one acetabular fracture). Fourteen cats were euthanased as a direct result of a fracture occurring. While most pelvic fractures healed uneventfully, some cats remained intermittently lame, but it was not always possible to determine the cause of the lameness from the information available and because all cats had concurrent patellar fractures.

Conclusions and relevance

Many of the pelvic fractures healed with conservative management. Fractures involving articular surfaces such as acetabular fractures may benefit from surgical stabilisation as surgery may offer the benefits of articular fracture repair with improved joint congruency and a faster return to normal activity.

Role of an additional third screw in the fixation of transverse patellar fracture with two parallel cannulated screw and anterior wire

BACKGROUND

Two parallel cannulated screws along with an anterior wire to construct a tension band is a popular approach in transverse patellar fractures. However, the optimal screw proximity, either deep or superficial screw placements, remains controversial. Hence, a new concept of the addition of a third screw to form a triangular configuration along with the original two parallel screws was proposed in this study. Therefore, the biomechanical effect of the additional third screw on the stability of the fractured patella was investigated with finite element (FE) simulation.

METHODS

An FE knee model including the distal femur, proximal tibia, and fractured patella (type AT/OTA 34-C) was developed in this study. Four different screw configurations, including two parallel cannulated screws with superficial (5-mm proximity) and deep (10-mm proximity) placements and two parallel superficial screws plus a third deep screw, and two parallel deep screws plus a third superficial screw, with or without the anterior wire, were considered for the simulation.

RESULTS

Results indicated that the addition of a third screw increased stability by reducing the dorsal gap opening when two parallel screws were deeply placed, particularly on the fractured patella without an anterior wire. However, the third screw was of little value when two parallel screws were superficially placed. In the existence of two deep parallel screws and the anterior wire, the third screw reduced the gap opening by 23.5% (from 1.15 mm to 0.88 mm) and 53.6% (from 1.21 mm to 0.61 mm) in knee flexion 45° and full extension, respectively. Furthermore, in the absence of the anterior wire, the third screw reduced the gap opening by 73.5% (from 2 mm to 0.53 mm) and 72.2% (from 1.33 mm to 0.37 mm) in knee flexion 45° and full extension, respectively.

CONCLUSION

Based on the results, a third cannulated screw superficially placed (5-mm proximity) is recommended to increase stability and maintain contact of the fractured patella, fixed with two parallel cannulated screws deeply placed (10-mm proximity), particularly when an anterior wire was not used. Furthermore, the third screw deeply placed is not recommended in a fractured patella with two parallel superficial screws.

Patient-reported outcomes of 7133 distal femoral, patellar, and proximal tibial fracture patients: A national cross-sectional study with one-, three-, and five-year follow-up

BACKGROUND

Few studies have described patient-reported outcome measures (PROMs) in knee fracture patients. We reported knee-specific and generic median PROM scores after knee fracture and identified risk factors for poor outcome defined by low median PROM scores.

METHODS

In a Danish cross-sectional study of 7133 distal femoral, patellar, and proximal tibial fracture patients during 2011-2017, OKS, FJS-12, EQ5D-5L Index, and EQ5D-5L Visual Analogue Scale (VAS), were collected electronically (response rate 53%; median age 60; 63% female). Poor outcome was defined as score lower than median PROM score. Poor outcome risk factors were estimated as odds ratios from binary logistic regression models.

RESULTS

At 0 to one year after knee fracture, median PROM scores were 31 (OKS), 27 (FJS-12), 0.50 (EQ5D-5L Index), and 74 (EQ5D-5L VAS). At >5 years after knee fracture, median OKS score was 40, median FJS-12 score was 54, median EQ5D-5L Index was 0.76, and median EQ5D-5L VAS score was 80. Age > 40 years had higher odds for poor OKS and FJS-12 scores at short- and long-term follow-up after knee fracture. Comorbidity burden, distal femoral fracture, and treatment with external fixation and knee arthroplasty were risk factors for poor outcome at long-term follow-up, for all four PROMs.

CONCLUSIONS

Although knee fracture patients have relatively high knee function and quality of life, their ability to forget about the knee joint after knee fracture is compromised. We identified several important risk factors for poor outcome measured by PROMs at different follow-up periods following knee fracture, which will help direct future quality-improvement initiatives.

Vertical Interfragmentary Doubled Suture for Displaced Patella Fractures: Sequential Compressive Tightening with Nice Knot

In the treatment of displaced patella fractures, open reduction and internal fixation is essential for patellofemoral congruency and restoration of the knee extension mechanism. Various surgical techniques and materials can be used, and their clinical outcomes are favorable. However, soft-tissue and skin irritation, pain, and limited range of motion due to metallic hardware can occur, and removal of hardware such as screws and K-wire may be required after bony union. We present a vertical interfragmentary suture technique for patella fractures using sequential compressive tightening with the Nice knot. This knot-tying technique is low profile, provides stable fixation enough to hold displaced fractures, and does not require a secondary procedure for hardware removal.

A comparison of EFECE systems with tension band wiring for patella fracture fixation in cadavers

Background

EFECE systems are newly defined internal fixation systems, which are suitable for patella fracture fixation. The aim of this study was to compare the fixation strength of EFECE Systems with tension band wiring for transverse patellar fracture simulation on fresh frozen cadaver models.

Methods

Quadriceps tendon-patella-patellar tendon (QT-P-PT) complex was prepared from human cadavers. After simulation of a transverse patella fracture, in group 1, 5 patella were fixed with a pair of 1.2 mm EFECE wires and 4 EFECE devices. In group 2, 5 patella were fixed with a pair of 1.2 mm Kirschner wires (K-wire) and a cerclage wire according to the tension band technique.

Using a testing device with custom-made jaws, increasing distraction force was applied to these QT-P-PT complexes. Extension of these complexes with the distraction forces was observed. The maximum distraction force and the elongation during maximum force were evaluated.

Results

After 5 experiments with the EFECE systems, there was no EFECE wire breakage or EFECE wire-EFECE device catching failure. The median maximum force was 740 N (720-810 N). During maximum distraction force the median extension was 2.5 mm (1.6-2.5 mm). After 5 experiments with the tension band technique, there was no K-wire breakage. The median maximum force was 330 N (240-510 N). During this maximum distraction force the median extension was 3.4 mm (2.2-3.8 mm).

Conclusions

Based on the biomechanical advantages, patella fracture treatment with EFECE systems may constitute a reasonable alternative in the treatment of patella fractures.

Predicting the risk of sarcopenia in elderly patients with patellar fracture: development and assessment of a new predictive nomogram

Purpose

To develop a risk prediction model for postoperative sarcopenia in elderly patients with patellar fractures in China.

Patients and methods

We conducted a community survey of patients aged ≥55 years who underwent surgery for patellar fractures between January 2013 and October 2018, through telephone interviews, community visits, and outpatient follow-up. We established a predictive model for assessing the risk of sarcopenia after patellar fractures. We developed the prediction model by combining multivariate logistic regression analysis with the least absolute shrinkage model and selection operator regression (lasso analysis) as well as the Support Vector Machine (SVM) algorithm. The predictive quality and clinical utility of the predictive model were determined using C-index, calibration plots, and decision curve analysis. We also conducted internal sampling methods for qualitative assessment.

Result

We recruited 137 participants (53 male; mean age, 65.7 years). Various risk factors were assessed, and low body mass index and advanced age were identified as the most important risk factor (P < 0.05). The prediction rate of the model was good (C-index: 0.88; 95% CI [0.80552–0.95448]), with a satisfactory correction effect. The C index is 0.97 in the validation queue and 0.894 in the entire cohort. Decision curve analysis suggested good clinical practicability.

Conclusion

Our prediction model shows promise as a cost-effective tool for predicting the risk of postoperative sarcopenia in elderly patients based on the following: advanced age, low body mass index, diabetes, less outdoor exercise, no postoperative rehabilitation, different surgical methods, diabetes, open fracture, and removal of internal fixation.

Treatment of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome

OBJECTIVES

The aim of this study is to describe the treatment and outcome of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice.

METHODS

Data were collated on cats with PADS that were reported to have sustained humeral fractures or had fractures or fissures of the humerus identified on radiographs. The details of the fractures were recorded in addition to any treatment and outcome information.

RESULTS

Of the 207 cases reported with PADS, 18 cats (8.7%) were found to have humeral condylar fractures, none of which was known to have resulted from significant trauma. Where treatment occurred, it involved the placement of transcondylar positional or lag screws. In some cases additional implants, including supracondylar bone plates and screws or Kirschner wires (K-wires), were used. Follow-up data revealed that only two cats were euthanased owing to the presence of the humeral fractures, with at least eight achieving some degree of recovery of function.

CONCLUSIONS AND RELEVANCE

These humeral fractures all have the characteristics of stress insufficiency fractures, being simple isolated fractures that are short oblique, with increased radio-density at the fracture line and occurring following minimal or no trauma. Humeral intracondylar fissures were identified in two cats and it is possible that some of the other fractures may have occurred secondary to pre-existing fissures. To our knowledge, no prior reports exist of fissures in cats that do not meet the criteria for PADS. Surgical repair primarily consisted of the placement of transcondylar lag or positional screws with, in some cases, adjunct implants such as bone plates and screws or K-wires. Though there were insufficient data to determine the prognosis for these fractures in the long term, unlike patellar fractures, many of these fractures will heal if treated appropriately.

Changes in patellar fracture characteristics: A multicenter retrospective analysis of 1596 patellar fracture cases between 2003 and 2017

PURPOSE

This study aimed to investigate the characteristics of patellar fracture and the changes in these characteristics over time in Korea.

METHODS

A total of 1596 patients with patellar fractures who visited 5 university hospitals from 2003 to 2017 were included in the analysis. The demographic characteristics of the patients, including age, sex, body mass index, and fracture characteristics, including the fracture classification, injury mechanism, fixation method, and postoperative complication rate, were analyzed through a review of the medical records and plain radiographs.

RESULTS

There were 988 (61.9%) male patients and 608 (38.1%) female patients. The mean age was 51.3 (range, 3-97) years for the study group, 47.6 (range, 8-94) years for male patients, and 57.3 (range, 3-97) years for female patients. Increasing trends in the proportion of patients aged ≥60 years and in the proportion of female patients were observed during the study period (p = 0.002 and p < 0.001, respectively). The fixation method also changed significantly during the study period, with decrease of the tension band wiring and increase of the combined method (p < 0.001). The incidence of high-energy injuries and more complex types of fracture was higher in male patients than in female patients (p < 0.001 and p < 0.001, respectively). Patients aged ≥60 years with patellar fractures showed a higher percentage of low-energy injuries and higher postoperative complication rates than younger patients (p < 0.001 and p = 0.002, respectively).

CONCLUSIONS

Patellar fractures in the female and elderly populations are increasing. Moreover, elderly patients with patellar fractures had a higher postoperative complication rate and also a higher percentage of low-energy injury than younger patients. Therefore, patellar fractures in the elderly population should be considered fragility fractures, and further studies are warranted to suggest a specific treatment plan for fragility patellar fractures.

Management of comminuted patellar fracture fixation using modified cerclage wiring

Background

Although there are several different kinds of fixation techniques for displaced comminuted patellar fracture, the treatment remains a challenge for orthopaedic surgeons. The purpose of this study is to evaluate the effectiveness and safety of a fixation technique for comminuted patellar fracture fixation using modified cerclage wiring.

Methods

From February 2016 to April 2018, 38 cases of simple unilateral closed comminuted patellar fracture were treated by modified cerclage wiring. Among these cases, 16 patients were males and 22 were females, aged 23–68 years (average 40.4 ± 9.1 years). Comminuted patellar fractures were classified according to the AO/OTA classification: 10 cases were type 34-C2 (three fragments), 28 cases were type 34-C3 (more than three fragments). Postoperative complications including loosening of internal fixation, fragment re-displacement, nonunion, infection, breakage of internal fixation and traumatic osteoarthritis were assessed. The clinical results after operation were evaluated by the clinical grading scales of Böstman including range of movement, pain, work, atrophy, assistance in walking, effusion, giving way, and stair-climbing during follow-up.

Results

A total of 38 patients were followed up for 6–36 months (mean time 16.1 ± 5.8 months). The bone union radiographically occurred at approximately 2.5–3.5 months (mean time 2.92 ± 0.25 months). No postoperative complications, such as infection, dislocation, breakage of the implants, painful hardware, and post-traumatic osteoarthritis, were observed. According to the clinical grading scales of Böstman, satisfactory results were obtained, and the mean score at the final follow-up was 28.7 (range 20–30) points. Thirty-two patients (84.2%) with excellent results had a mean score of 29.5 ± 0.7 (range 28–30) points, and six patients (15.8%) with good results had a mean score of 24.5 ± 2.2 (range 20–27) points. The patients with excellent and good scores had active flexion of 130° (110–140).

Conclusions

Modified cerclage wiring can effectively treat comminuted patellar fracture and offers a new strategy resulting in satisfactory results without obvious complications.

Extensor mechanism reconstruction with peroneus longus tendon autograft for neglected patellar fracture, report of 2 cases

Extensor mechanism deficiency in the knee may occur due to neglected patellar and quadriceps tendons rupture or may be caused by chronic fractures of the patella. Older patients can tolerate nonunion with impaired function including extension limitation or persistent muscle weakness. In young patients, performing rigid internal fixation with reoperation should be considered when a nonunion occurs. However, delayed and neglected nonunion in patella fractures require performing different surgical procedures. We report two cases, operated for a patella fracture, in whom nonunion occurred and accompanied by patellar migration and retraction of quadriceps tendon because of a fixation failure. We reconstructed the extensor mechanism with peroneus longus tendon autograft and, owing to this method, we achieved excellent functional results during a 2-year follow-up period.

Contourable craniofacial mesh plate osteosynthesis of patellar fractures: A new, low-profile fixation technique

PURPOSE

Patellar fractures are challenging orthopaedic injuries that can be difficult to treat due to the complexity of fracture patterns, the high stresses at the patellofemoral joint, and subcutaneous location of the patella. Hardware prominence and need for hardware removal are two of the most common complications after surgical fixation of patellar fractures. There is an ever present need for low profile fixation constructs that are also biomechanically stable.

MATERIALS AND METHODS

We present an alternative technique of patella fixation with a low profile titanium mesh plate typically used in craniofacial skeletal trauma. Four patients at our institution underwent mesh plate fixation of patella fractures.

RESULTS

All four patients had union without any post-operative complications. All four patients regained preoperative range of motion without residual pain or disability.

CONCLUSIONS

Mesh plate fixation of patellar fractures is an alternative to standard tension band technique, especially in comminuted fractures. The craniofacial mesh plate is very low profile, provides stable fixation that allows for early range of motion, and has the potential to reduce post-operative complications like hardware removal.

A novel three-dimensional strapping reduction for the treatment of patellar fractures

Objective

This study aimed to investigate the effectiveness of a three-dimensional strapping reduction in the treatment of patellar fractures.

Methods

Between January 2015 and June 2017, a total of 56 patients were randomly allocated to the three-dimensional strapping reduction group (trial group) and towel clamp reduction group (control group). There were no significant differences in age, gender, injury side, the interval time from injury to surgery, fracture pattern, and cause of injury (P > 0.05). The operation time, fluoroscopy time, bone union time, postoperative Hospital for Special Surgery (HSS) scores, and complications were recorded and analyzed.

Results

All incisions achieved primary union. All patients in both groups completed a follow-up with an average of 12.5 months (range 11–15 months). Both operation time and fluoroscopy time in the trial group were significantly shorter than those in the control group (P < 0.001). All patellar fractures achieved bone union, and there was no significant difference in bone union time between the two groups (P > 0.05). Bone nonunion, infection, and fixation failure were not found in both groups. HSS scores of the trial group (90.9 ± 4.2) were higher than those of the control group (86.6 ± 5.2) (P < 0.01).

Conclusion

Compared with towel clamp reduction, the three-dimensional strapping reduction in the treatment of patellar fractures has advantages of shorter operation time and fluoroscopy time, better knee function after surgery, and satisfactory fracture healing.

Patellar complications following total knee arthroplasty: a review of the current literature

Total knee arthroplasty is a common operation for treating patients with end-stage knee osteoarthritis and generally has a good outcome. There are several complications that may necessitate revision of the implants. Patella-related complications are difficult to treat, and their consequences impact the longevity of the implanted joint and functional outcomes. In this review, we explore the current literature on patellar complications in total knee arthroplasty and identify risk factors as well as strategies that can help in preventing these complications. We present pertinent findings relating to patellar complications. They can be classified into bony or soft tissue complications and include bone loss, aseptic loosening, periprosthetic fractures, patella fracture, patellar clunk syndrome, patellofemoral instability, extensor mechanism complications, maltracking, patella baja and malrotation. We conclude that patellar complications in total knee arthroplasty are common and have significant implications for the functional outcome of total knee arthroplasty. A high index of suspicion should be maintained in order to avoid them. Implant malpositioning and other forms of intraoperative technical error are the main cause of these complications, and therefore, primary prevention is crucial. When dealing with these established problems, a clear plan of action should be formulated in advance to allow appropriate management as well as anticipation of adverse outcomes.

Roles of the screw types, proximity and anterior band wiring in the surgical fixation of transverse patellar fractures: a finite element investigation

BACKGROUND

Cannulated screws with an anterior wire are currently used for managing transverse patellar fracture. However, the addition of anterior wiring with various types of screws via open surgery to increase the mechanical stability is yet to be determined. Hence, this study aimed to compare the mechanical behaviors of a fractured patella fixed with various screws types and at various screw locations with and without the anterior wire. The present study hypothesized that using the anterior wire reduces the fracture gap formation.

METHODS

A finite element (FE) model containing a fractured patella fixed with various types of cannulated screws and anterior wiring was created in this study. Three types of screws, namely partial thread, full thread, and headless compression screws, and two screw depths, namely 5 and 10 mm away from the anterior surface of the patella, were included. The effect of the anterior wire was clarified by comparing the results of surgical fixation with and without the wire. Two magnitudes and two loading directions were used to simulate and examine the mechanical responses of the fractured patella with various fixation conditions during knee flexion/extension.

RESULTS

Compared with partial thread and headless compression screws, the full thread screw increased the stability of the fractured patella by reducing fragment displacement, fracture gap formation, and contact pressure while increasing the contact area at the fracture site. Under 400-N in the direction 45°, the full thread screw with 5-mm placement reduced the gap formation by 86.7% (from 2.71 to 0.36 mm) and 55.6% (from 0. 81 to 0. 36 mm) compared with the partial thread screw with 10-mm placement, respectively without and with the anterior wire.

CONCLUSION

The anterior wire along with the full thread screw is preferentially recommended for maintaining the surgical fixation of the fractured patella. Without the use of anterior wiring, the full thread screw with 5-mm placement may be considered as a less invasive alternative; however, simple screw fixation at a deeper placement (10 mm) is least recommended for the fixation of transverse patellar fracture.

[Plate osteosynthesis after patellar fracture - the technique and initial results of a prospective study]

BACKGROUND

Tension band wiring after patellar fractures is related to a high number of implant-related complications (22-53 %). Revision surgery is necessary in 10-55 % of patients mostly with unsatisfactory results. The patella plate is an alternative treatment with the advantages of locked plating. The purpose of this study was to evaluate the first clinical prospective results and complications of this new implant.

MATERIALS AND METHODS

Between April 2013 and May 2015 all patients that were treated with locked plating for patella fractures were included in this prospective study. Patients were followed-up clinically after six weeks and six months.

RESULTS

Included in this study were 17 patients, 6 women and 11 men, with a mean age of 58 years (19-87). The knee range of motion was 120° after 6 weeks and improved to 138° after 6 months, corresponding to 84 % and 97 % of the range of motion of the healthy opposite knee. The Tegner activity scale increased from 2,5 to 3,5 (initial value: 4), the Lysholm score increased from 78 to 92 points (initial value: 97) and the Kujala score increased from 72 to 88 points (initial value: 96). Two complications occurred: one patient had a reactive bursitis prepatellaris and one patient sustained a loss of reduction.

CONCLUSION

Locked plating of patella fractures is a reliable alternative treatment with good functional outcomes and low complication rates.

[Clinical study of three-dimensional strapping reduction in treatment of patellar fracture]

Objective

To investigate the effectiveness of three-dimensional strapping reduction in treatment of patellar fracture.

Methods

Between January 2015 and June 2015, thirty-two patients were randomly allocated to three-dimensional strapping reduction group (trial group) and towel clamp reduction group (control group). There was no significant difference in age, gender, damage side, interval from injury to opreration, fracture pattern, and cause of injury ( P>0.05). The operation time, fluoroscopy time, fracture healing time, postoperative Hospital for Special Surgery (HSS) scores, and complications were collected and analysed.

Results

All incisions healed at stage I. All patients of 2 groups were followed up 10-14 months (mean, 12.4 months). The operation time and fluoroscopy time of trial group were both shorter than those of control group ( t=6.212, P=0.000; t=6.585, P=0.000). X-ray films showed that the fractures in both groups healed successfully and there was no significant difference in healing time between groups ( t=1.973, P=0.058). Bone nonunion, infection, and failure fixation were not found in both groups. HSS scores of trial group (91.6±3.8) was higher than that of control group (86.4±5.5) ( t=-3.105, P=0.004).

Conclusion

Compared with towel clamp reduction, the three-dimensional strapping reduction in treatment of patellar fracture has the advantages of shorter operation time and fluoroscopy time, better knee function after operation, and satisfactory fracture healing.

[Effectiveness of cerclage and a figure-of-eight tension band by a single titanium wire in treatment of patellar fracture]

Objective

To estimate the outcome of cerclage followed by a figure-of-eight tension band with a single titanium wire for the treatment of patellar fracture.

Methods

A retrospective analysis was made on the clinical data of 46 patients with patellar fractures treated between June 2012 and November 2014. There were 30 males and 16 females, aged 20-86 years (mean, 54 years). The fracture causes included falling in 27 cases, traffic accident in 16 cases, and knock in 3 cases. There were 41 cases of closed fractures and 5 cases of open fracture. The injury located at the left side in 24 cases and the right side in 22 cases. According to AO classification, fracture was rated as type 34-A in 3 cases, as type 34-B in 1 case, as type 34-C1 in 7 cases, as type 34-C2 in 13 cases, and as type 34-C3 in 22 cases. The time between injury and operation ranged 1-12 days (mean, 3.7 days). During operations, a single titanium wire was used to pass around the patellar, followed a figure-of-eight wrapping, to tight and fix at the tension of 35 kg.

Results

All incisions healed primarily. The patients were followed up 20.6 months on average (range, 6-24 months). Partial wire loosening was found in 2 cases, irritation of skin or soft tissue in 1 case. The X-ray examination showed bony healing at 3 months after operation, without breakage of titanium wire. The internal fixation was removed in 38 cases at 12 months after operation. According to the Böstman rating score, the mean score was 28.34 (range, 24-30) at 12 months after ope-ration; the results were excellent in 42 cases and good in 4 cases, with an excellent and good rate of 100%.

Conclusion

For patellar fracture, cerclage followed by a figure-of-eight tension band with a single titanium wire is able to achieve an effective stability and to allow early motion for patient with less complication.

Five-pointed star lattice sutures for fixation of patella transverse fractures: a clinical study

INTRODUCTION

Fixation of displaced patella fractures with metal implants may be associated with implant failure, post-operative pain, and high re-operation rate. This study reports preliminary clinical results of using five-pointed star lattice sutures for the management of patella transverse fractures.

METHODS

A five-pointed star lattice suture configuration was produced intraoperatively, and 25 patients with patella transverse fractures were treated with this newly designed sutures fixation. All patients were followed up until union of the fractures or until further surgical intervention. At a mean of 1.6 years (range 0.8-2.5 years) of follow-up, the notes and plain radiographs of the 25 patients were reviewed. Bostman score was used to evaluate the therapeutic effects.

RESULTS

All 25 patients experienced union of the patella fractures, with excellent knee function in 19 patients and good in 6 patients evaluated with Bostman score.

CONCLUSION

The newly designed five-pointed star lattice sutures fixation may be a feasible alternative to metal implants fixation in the management of patella transverse fracture.

LEVEL OF EVIDENCE

Level IV case series.

[Effectiveness of high strength suture fixation in treatment of patellar transverse fracture]

Objective

To explore the effectiveness of high strength suture fixation in treatment of patellar transverse fracture.

Methods

Between June 2014 and June 2016, 38 patients with the patellar transverse fracture were treated with high strength suture internal fixation. There were 24 males and 14 females with the age of 26 to 64 years (mean, 45 years). There were 6 cases of accident injury and 32 cases of crashing injury. The time interval between injury and surgery was 2-8 days (mean, 5 days). The preoperative visual analogue scale (VAS) score, Lysholm score, and range of motion (ROM) of patients were 84.3±8.4, 44.5±7.2, and (62±12)°, respectively.

Results

All patients' incisions healed by first intention after operation. There was no neurovascular injury, deep venous thrombosis of lower limbs, or local foreign matter irritation reaction. The X-ray films showed that the reduction of patella and the location of internal fixator were good at 2 days after operation. All the 38 patients were followed up 12-18 months (mean, 16 months). All fractures healed and the healing time was 2-4 months (mean, 3 months). At last follow-up, according to the Böstman criteria, 36 patients were rated as excellent and 2 as good, with an excellent and good rate of 100%. The VAS score, Lysholm score, and ROM of patients were 10.2±6.6, 93.1±6.4, and (124±14)°, respectively, showing significant differences when compared with preoperative ones ( t=42.759, P=0.000; t=31.099, P=0.000; t=20.727, P=0.000).

Conclusion

Application of high strength suture fixation in the treatment of patellar transverse fracture has advantages of simple to operate, effective fixation, and less complication. It can avoid reoperation of removing the internal fixators. The satisfied ROM and function of the knee joint can be obtained after operation.