Comparison of the outcomes of cannulated screws vs. modified tension band wiring fixation techniques in the management of mildly displaced patellar fractures

Dual tension band technique for patellar fractures involving articular surface and inferior pole: a retrospective cohort study and finite element analysis

Background

Fractures involving the inferior pole of the patella can lead to postoperative patella baja. For comminuted patellar fractures that affect both the articular surface and the inferior pole, we aim to explore a new fixation method that provides reliable internal stabilization while reducing the incidence of patella baja.

Methods

We conducted a finite element biomechanical study and a retrospective cohort clinical study. The finite element analysis compared the "dual tension band" technique to the traditional single tension band method using 3D models of patellar fractures. The clinical study included 66 patients with patellar fractures involving the articular surface and inferior pole, divided into two groups based on the fixation method. Outcomes were assessed using a range of motion (ROM), Böstman scores, and the Insall-Salvati Index (ISI).

Results

The finite element analysis revealed that the dual tension band technique resulted in lower maximum stress on the patella and lower displacement on the fixation devices compared to the single tension band. Clinically, patients treated with the dual tension band had significantly higher postoperative ISI values (0.93 ± 0.16 vs. 0.85 ± 0.17, p < 0.05), better ROM (123.75 ± 9.58 vs. 117.63 ± 12.28, p < 0.05), and a lower incidence of patella baja (17.86% vs. 34.21%). The Böstman scores showed no significant difference between the groups.

Conclusion

The dual tension band technique provides effective stabilization for patellar fractures involving the articular surface and inferior pole, reducing the incidence of postoperative patella baja and improving functional outcomes.

Tension band tendon-approximating cerclage for surgical fixation of patellar fractures: a novel surgical technique

Patellar fractures are potentially debilitating injuries due to loss of extensor mechanism function, resulting in an inability to extend the leg. Traditionally, these fractures have been surgically managed with open reduction and internal fixation using a tension band construct. This can be performed with K-wires or cannulated screws with suture or cable as the tension band. Plate osteosynthesis is another option that is increasing in popularity. Incorporating the tension band construct converts tensile force into a healing-compatible compressive force. However, these techniques often fail when used for comminuted patellar fractures. There is also a high reoperation rate due to metal implant discomfort. Reoperation rates have been reported as high as 41% for K-wires and 23% for cannulated screws. A more optimal technique would provide adequate reduction and strong fixation without the risk of implant irritation that can apply to all/most fracture types. We report a new technique that implements a multistrand, long-chain, ultra-high-molecular weight, polyethylene core suture material with a braided jacket of polyester (FiberWire) without the need for any associated plates, K-wires, or cannulated screws. The suture is woven to create a tension band tendon-approximating cerclage construct that incorporates the proximal and distal bone fragments as well as the patellar and quadriceps tendons. This technique can be used for both simple and comminuted fractures and provides optimal fixation strength while minimizing the complications associated with metal implants. The efficacy of this technique may lend to future studies including biomechanical and retrospective analyses.

Cannulated compression screws with cable technique leads to a dramatic reduction in patella fracture fixation complications compared to tension band wiring

INTRODUCTION

The aim of this study was to compare the clinical, radiological and functional outcomes between cannulated compression screw with cable construct (CS) and tension band wiring (TBW) in transverse patella fractures.

MATERIALS AND METHODS

A retrospective study was conducted on patients surgically treated for AO/OTA 34C1 or 34C2 transverse patella fractures with CS or TBW technique between January 2019 and January 2023. Clinical outcomes included complications related to the implant, wound and fracture at 6 months and 1 year, time to achieving full weight bearing status and early perioperative clinical outcomes. Radiological outcomes included the time to fracture heals and delayed union. Functional outcome measures using the Oxford Knee Scale, 36-short form questionnaire and the Bartlett Anterior Knee Score were assessed.

RESULTS

73 patients were treated with CS (n = 33) or TBW (n = 40). TBW had higher complication rates: 25.0% (n = 10) required implant removal, 12.5% (n = 5) had wire breakage, 12.5% (n = 5) experienced fracture displacement while 52.5% (n = 21) experienced implant migration. In contrast, no CS patients had implant removals, wire breakage or fracture displacement and 3.0% (n = 1) experienced implant migration. At 1 day post-operatively, 87.9% (n = 29) CS group patients were able to ambulate as compared to the 55.0% (n = 22) of TBW patients. Furthermore, CS patients ambulated further distances at 11.8 ± 10.6 m than the TBW group (6.4 ± 7.4 m). The CS group (25.9 ± 24.6 days) also achieved full weight bearing status faster than the TBW group (43.6 ± 39.4 days). The time taken for the fracture to heal and functional outcomes were comparable among the two groups.

CONCLUSIONS

The CS technique demonstrated lower complications, in particular, no CS patient had implant removals, wire migration or fracture displacement. Additionally, CS technique showed a faster return to ambulation and time to achieving full weight bearing status.

A novel technique for treating simple transverse patellar fractures using cannulated screws: a cadaveric and clinical study

BACKGROUND

Tension band wiring (TBW) has conventionally been used for the open reduction and internal fixation of the patella. However, it suffers from distinct disadvantages such as large incision, implant irritation, and need for subsequent implant removal. Here, we propose a novel technique using closed reduction and percutaneous fixation with three cannulated screws (TCS), which may be an alternative to this established conventional technique. Although some researchers have proposed alternative methods including closed reduction and cannulated screw fixation, with or without additional wires through the screws, and arthroscopic-assisted reduction and fixation, there are few studies that focus on the biomechanical stability of percutaneous fixation using only cannulated screws. Thus, the purpose of this study was to evaluate TCS versus TBW for simple transverse patellar fractures in cadaveric and patients' level, aiming to determine whether TCS show superiority over TBW in terms of biomechanical stability in a cadaveric study with benign clinical feasibility and outcomes in patients.

METHODS

We conducted a cadaveric study with 15 knee specimens that had simple transverse patellar fractures. We used two fixation techniques: TBW (group A, n = 6) and TCS (group B, n = 9). We applied sinusoidal forces (25 N-125 N) at 1/5 Hz and 90° knee flexion to simulate knee movement. We compared the displacements at the fracture site between the two groups. We also used the same technique in a total of 23 patients and followed up them for at least 1 year.

RESULTS

TCS demonstrated favourable biomechanical stability in the cadaveric study. The technique also performed excellently in terms of postoperative pain, knee function recovery, and complication rates during the follow-up period.

CONCLUSIONS

The technique provides a surgical treatment option with small incisions, minimal soft tissue irritation, and possibly lower removal rate of bothersome material.

A Comparison of the Efficacy of Cannulated Screws against Modified Tension Band Wire in the Management of Slightly Displaced Fractures of the Patella: A Novel Technique

AIM

The study aimed to compare the outcomes of Open Reduction and Cannulated Screw Fixation (ORCF) and Open Reduction and Tension Band Wire Fixation (ORTF) for treating minimally displaced patellar fractures, with the intention to discern the more efficacious surgical method in terms of various clinical and radiographic parameters.

METHODS

The research was a retrospective controlled trial encompassing 63 patients, culminating in a final data set of 52 patients with transverse patellar fractures with less than 8 mm of displacement. Patients were assessed postoperatively at three, six, and twelve months using measures such as the Lysholm score, Visual Analog Scale (VAS) for pain, and goniometry for active knee extensions and flexion. Statistical analyses were performed using SPSS version 22.0.

RESULTS

Results indicated superior clinical outcomes for the ORCF group at twelve months post-treatment, with notable higher Lysholm scores and lower VAS scores for pain at three-, six-, and twelve-month intervals. The ORCF group also demonstrated improved flexion and range of motion, with an average fracture healing time of 2.65 months and significantly lower complication rates, compared to the ORTF group.

CONCLUSIONS

The ORCF method, leveraging headless compression screws and cerclage wire fixation, emerges as a promising approach for managing minimally displaced transverse patellar fractures, potentially offering improved clinical results and patient satisfaction in comparison to the traditional ORTF method. Further expansive and diverse studies are warranted to substantiate these findings.

A study of fracture lines distribution characteristics in complete articular fractures of the patella

Objective

The objective of this study was to unveil the characteristics of fracture lines distribution and explore its clinical significance of complete articular fractures of the patella.

Methods

A consecutive series of image data from 88 patients with complete articular patella fractures were retrospectively included. Three-dimensional reconstruction images of the patella fractures were created and collected. Subsequently, these reconstructed images were visually overlaid onto a standard anterior and posterior patella template. The fracture lines were then identified, traced onto the template, and utilized to generate patella fracture maps. Furthermore, the incidence rate of patella fracture lines involving the distal pole was analyzed.

Results

The maps depict the fracture lines of complete articular patella fractures. For simple and complex patella fractures, the primary fracture lines primarily converge within the Middle and Lower regions, exhibiting a transverse pattern. Conversely, the primary fracture lines in comminuted patella fractures are randomly dispersed across the patella. Examining the maps, approximately 63.6% (56/88) of complete articular patella fractures exhibited involvement of the distal pole in the anterior view, while 48.9% (43/88) displayed distal pole fractures in the posterior view. The incidence of distal pole injury increased progressively with the severity of patella fractures.

Conclusion

The patterns and distribution of fracture lines in cases of complete articular patella fractures are prominently illustrated on the constructed fracture maps. Familiarity with these common characteristics of complete articular patella fracture, especially with the distal pole injury, can aid surgeons in developing preoperative planning, executing surgical strategies effectively, and reducing inappropriate treatment.

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.

Pin and Wire System Fixation for the Treatment of Comminuted Patella Fractures

We describe the wiring technique and evaluate the radiographic and clinical outcomes of treatment with a pin and wire system (PWS) for comminuted patella fractures. From June 2013 to October 2018, 33 patients with comminuted patella fractures were treated using a PWS. Open reduction and internal fixation was performed with multiple pins and a wire. All patients were allowed full weight bearing without a brace. Radiographs were obtained to evaluate bone union, implant breakage, back-out of pins, and intra-articular gaps and step-off. Clinical outcomes and postoperative complications were assessed at final follow-up examination. All fractures were united. Thirteen cable wires in 13 patients were partially broken without displacement of fracture at an average of 7.4 months (range, 1-19 months) postoperatively. The average preoperative, postoperative, and final follow-up intra-articular gap and step-off were 11.7 mm, 0.5 mm, and 0.03 mm and 6.6 mm, 0.4 mm, and 0.2 mm, respectively. The average postoperative pin displacement was 0.1 mm (range, 0-0.8 mm). Deep infection was not observed after the surgery. The implant removal rate was 21% (7 of 33). Among these, the symptomatic implant removal rate was 9% (3 of 33). Additionally, 3 of 7 patients with implant removal had broken wires. The average flexion and extension of knee joints were 139.7° (range, 120°-150°) and -0.9° (range, -10° to 0°), respectively. A PWS prevents back-out of the pins and reduces intra-articular gaps and step-off distances to acceptable levels, even if the cable wire is partially broken. Therefore, a PWS is a good treatment option for comminuted patella fractures. [Orthopedics. 2023;46(5):291-296.].

Comparison of a minimally invasive osteosynthesis technique with conventional open surgery for transverse patellar fractures

PURPOSE

The study aims to compare the efficacy and safety of a new minimally invasive osteosynthesis technique with those of conventional open surgery for transverse patellar fractures.

METHODS

It was a retrospective study. Adult patients with closed transverse patellar fracture were included, and with open comminuted patellar fracture were excluded. These patients were divided into minimally invasive osteosynthesis technique (MIOT) group and open reduction and internal fixation (ORIF) group. Surgical time, frequency of intraoperative fluoroscopy, visual analogue scale score, flexion, extension, Lysholm knee score, infection, malreduction, implant migration and implant irritation in two groups were recorded and compared. Statistical analysis was performed by the SPSS software package (version 19). A p < 0.05 indicated statistical significance.

RESULTS

A total of 55 patients with transverse patellar fractures enrolled in this study, the minimally invasive technique was performed in 27 cases, and open reduction was performed in 28 cases. The surgical time in the ORIF group was shorter than that in the MIOT group (p = 0.033). The visual analogue scale scores in the MIOT group were significantly lower than those in the ORIF group only in the first month after surgery (p = 0.015). Flexion was restored faster in the MIOT group than that in the ORIF group at one month (p = 0.001) and three months (p = 0.015). Extension was recovered faster in the MIOT group than that in the ORIF group at one month (p = 0.031) and three months (p = 0.023). The recorded Lysholm knee scores in the MIOT group were always greater than those in the ORIF group. Complications, such as infection, malreduction, implant migration, and implant irritation, occurred more frequently in the ORIF group.

CONCLUSION

Compared with the ORIF group, the MIOT group reduced postoperative pain and had less complications and better exercise rehabilitation. Although it requires a long operation time, MIOT may be a wise choice for transverse patellar fractures.

Management and Outcome of Elderly Patients With Patellar Fracture Treated With Novel Modified Cerclage Wiring

Introduction

The purpose of this study is to assess the efficacy and security of a fixation method for fixing patellar fractures in elderly patients utilizing modified cerclage wire.

Methods

From January 2015 to December 2020, 31 cases (age≥65 years old) of closed patellar fracture were treated by modified cerclage wiring. Patients in these instances ranged in age from 65 to 87 (73.7 ± 7.2 years), with 15 men and 16 women. 4 instances were type 34-C1 (transverse fracture) according to the AO/OTA classification, 27 cases (87%) were comminuted fractures, including 11 cases that were type 34-C2 (3 fragments), and 16 cases that were type 34-C3 (more than 3 fragments). Postoperative problems such as fragment re-displacement, nonunion, internal fixation loosening, infection, and internal fixation rupture were evaluated. The clinical grading systems of Böstman were used to assess the postoperative clinical outcomes.

Results

Thirty one patients in all were monitored for 14 to 31 months (22.2 ± 4.5 months). After the procedure, the fracture took 2.5-3.5 months (2.92 ± .25 months) to heal. There were no postoperative issues like infection, dislocation, implant breakage, uncomfortable hardware, or post-traumatic osteoarthritis. According to the clinical grading scales of Böstman, the average score of the final follow-up was 28.6 ± 1.1 (range 26-30). 29 (94%) of the patients had excellent results, whereas just 2 (6%) had good results. The patient's knee flexion activity ranged from 110 to 140°, making for a favorable prognosis.

Conclusion

Most patella fractures in the elderly are comminuted. Elderly patients with patellar fractures may be successfully treated with modified cerclage wire, with good results and no noticeable side effects.

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.

Clinical Outcomes of Cannulated Screws versus Ring Pin versus K-Wire with Tension Band Fixation Techniques in the Treatment of Transverse Patellar Fractures: A Case-Control Study with Minimum 2-Year Follow-Up

Purpose. K-wire with tension band (KTB) technique has long been the primary surgical method for transverse patella fractures; however, it also has shortcomings. This study is aimed at evaluating the three different techniques to see whether the cannulated screw tension band (CSTB) or ring pin tension band (RPTB) techniques could decrease complications and achieve better knee function compared with KTB. Methods. We conducted a retrospective comparison of the KTB, CSTB, and RPTB fixation techniques. We selected and reviewed 90 patients (30 patients in each fixation group) with follow-up at least 2 years. Duration of operation, intraoperative blood loss, mean healing time, visual analog scale score, range of motion, Böstman score, Iowa knee score, modified Lysholm rating scale, and postoperative complications were compared. Multivariate analyses were performed to identify the independent risk factors for fracture healing time, postoperative complications, and knee function recovery. Results. After adjusting for confounding factors, multivariate regression analysis revealed that CSTB was 0.26 times (95% CI: 0.08-0.86, $p=0.027$ ) less likely to prolong fracture healing time, 0.20 times (95% CI: 0.06-0.64, $p=0.007$ ) lesser risk of postoperative complications, and more than four times (95% CI: 1.41-13.56, $p=0.011$ ) as likely to improve the knee function score compared with KTB. Besides, RPTB were also superior to KTB in reducing the incidence of postoperative complications (OR: 0.21, 95% CI: 0.07-0.64, $p=0.006$ ) and improved knee function score (OR: 3.96, 95% CI: 1.30-12.08, $p=0.016$ ); however, the CSTB group being more superior. In addition, AO/OTA C2 fractures (OR, odds ratio: 10.68, 95% CI: 1.30-87.70, $p=0.027$ ) and high-energy fracture (OR: 8.78, 95% CI: 1.57-49.17, $p=0.013$ ) were also associated with prolonged fracture healing time but not with postoperative complications and knee function. No significant differences in related indicators such as gender, age, BMI, AO/OTA classification, fracture side, injury mechanism, duration of operation, and intraoperative blood loss were detected among the three groups. Conclusion. This study demonstrated that the CSTB technique is superior to KTB and RPTB techniques in reducing the incidence of postoperative complications, and it also has advantages in accelerating fracture healing, achieving better VAS, ROM, and functional recovery. Further long-term large-sized prospective randomized trials are needed to evaluate the efficacy of the KTB in treating transverse patellar fractures.

Lag screw osteosynthesis of simple olecranon fractures: A biomechanical comparative study

Olecranon fractures are most frequently stabilized by tension band wiring (TBW), which unfortunately leads to relevant implant removal rates due to K-wire migration and soft tissue irritation. As lag screw osteosynthesis (LSO) might be a gentle and effective alternative in simple fracture patterns, the goal of the present study was to biomechanically compare LSO with TBW in simple olecranon fractures at a cadaver model. A simple olecranon fracture (Mayo type IIA) was created in eight pairs of human cadaver elbows, which were pairwise fixed by either TBW or two transcortical 4.0 mm lag screws. Biomechanical testing was conducted as a pulling force, applied to the triceps tendon in a 90° position. First, cyclic loading between 10 and 300 N was performed for 50,000 cycles. Afterward, maximum load was raised by 0.02 N/cycle until construct failure, what was defined as displacement >2 mm. Besides fracture displacement, failure cycle and failure load, the modes of failure were analyzed. Within the first five cycles, there was no significant difference in displacement (median TBW: 0.2 mm; LSO: 0.5 mm; p = 0.091). Both after 2000 (median TBW: 0.2 mm; LSO: 0.6 mm; p = 0.042) and after 20,000 cycles (median TBW: 0.4 mm; LSO: 0.9 mm; p = 0.027), the difference was significant. Failure cycle (median TBW: 72,639 cycles; LSO: 43,429 cycles; p = 0.017) and failure load (median TBW: 702 N; LSO: 303 N; p = 0.025) differed significantly as well. TBW mostly (6/8) failed at the lock of the cerclage wire, whereas most LSO constructs (5/8) failed as a pullout of the proximal fragment. In conclusion, to our biomechanical findings at human cadaver specimens, simple olecranon fractures treated by LSO show higher dislocation rates and lower failure loads compared to conventional TBW and mostly fail by pullout of the proximal fragment.

Fracture-related infection of the patella: Treatment options and outcome

BACKGROUND

Fracture-related infection (FRI) after the operative management of patella fractures is a serious complication that can result in prolonged hospitalization, multiple revision procedures and permanent functional impairment. Till today, treatment modalities and outcome of FRI of the patella are not well described. Therefore, the main objective of this retrospective cohort study was to evaluate treatment options, functional outcome and healthcare costs related to FRI of the patella.

METHODS

This study evaluated 111 consecutive patients that were surgically treated for patella fractures, at the department of trauma surgery of the University Hospitals Leuven (Belgium), between January 2015 and April 2020. Patients were excluded if they (1) were younger than 18 years at the time of injury or (2) died during follow up. The minimal follow-up for all patients was 18 months.

RESULTS

During the 5-year study period, 107 patients with 108 patella fractures were included. A total of 10 patients were diagnosed with an FRI (9.3%). Four of these were treated with a DAIR approach and three patients underwent implant removal or exchange. Finally, three patients were treated with total patellectomy. Out of the 10 patients, two were diagnosed with a recurrence of infection. Overall, we observed substantial lower scores for all Knee Injury and Osteoarthritis Outcome Score subscales in the FRI group, compared to a reference population. Moreover, our study shows that direct hospital-related healthcare costs of FRI of the patella were nine times higher compared to non-FRI cases.

CONCLUSIONS

FRI of the patella is a challenging complication and recurrence of infection not uncommon. Although multiple treatment modalities exist, a multidisciplinary patient-specific approach is crucial. An early or delayed onset infection can be managed with a DAIR approach, but only when the construct is stable and the soft tissue coverage adequate. In patients with an FRI, implant removal is preferred when the fracture has healed. A total patellectomy can be used as a salvage procedure in complex cases with acceptable functional results. Overall, FRI of the patella leads to both a negative impact on the functional status of the patient and a ninefold increase in total healthcare costs.

Prospective Comparative Study of Fixing Displaced Transverse Patellar Fracture by Tension Band Wiring Versus Cannulated Screws with Wiring

BACKGROUND: Transverse fractures of the patella are important fractures with a wide variety of subtypes, the common incidence in the age group of 20–50 years. Surgical interference aims to achieve a perfect alignment of the joint surface, in addition to rigid fixation of the fracture for early re-habitation and early movement to retain the extensor mechanism of the knee joint. AIM: The aim of this study was to compare the radiological and functional outcomes of the displaced transverse patella fracture in adult patients treated by ORIF using tension band wiring versus cannulated screws with wiring. METHODS: A prospective analytic comparative study was conducted in Al-Kindy Teaching Hospital/Baghdad/Iraq for 18 months from April 1, 2019, to October 1, 2020. It included 32 patients with isolated displaced transverse patellar fracture AO type 34-C1. The patients have undergone operative fixation with two different surgical techniques divided randomly by choosing every other patient into two groups. Group A, the fracture was fixed by cannulated screws with wiring and Group B, the fracture was fixed by two K-wires and with tension band technique. Postoperatively, assessment of the knee function by Lysholm score, the visual analog scale for pain intensity, and active flexion range of movement were measured in degree as primary outcomes, while time to union in weeks assessed radiographically as secondary outcomes. RESULTS: The patients’ age was ranging from 26 to 49 years, with males predominant. Low-energy falls occupying a major part of the mechanism of injury in both groups. Lysholm score was significantly increased after 3, 6, and 12 months compared to that after 1 month in both groups with no statistical differences. The mean visual analog score significantly decreased in Group A after 1 month than that in Group B with no significant change in the other follow-up periods. There were no statistically significant differences in both groups regarding the range of knee movement and the radiographic assessment of fracture healing. CONCLUSION: Both techniques are good and effective with taking into consideration that open reduction and cannulated screws fixation with wiring technique is shown to be associated with lower post-operative pain and a lower frequency of complications mainly surgical site infection.

Comparison of Functional and Radiological Outcomes of Transverse Patellar Fractures Fixed with Tension Band Fixation Using Cannulated Screws and Kirschner Wires: A Prospective Randomized Study

PURPOSE

To compare functional and radiological outcomes of transverse patella fractures treated with tension band wiring using either two 4.5 mm cannulated screws or Kirshner wire.

METHODS

This is a non-blinded prospective randomized study comprising of two groups (n = 30 each) with closed transverse patella fractures treated with tension band wiring using Kirschner wire (K wire group) and two 4.5 mm cannulated screws (CCS group). Outcomes measured were radiological union, Knee Society score, range of motion and post-operative complications.

RESULTS

The CCS group showed a statistically significant higher range of motion than K wire group for each follow up (p < 0.001 in flexion and p < 0.005 in extension). A statistically significant higher percentage of patients in the CCS group showed signs of union at 6th and 12th post-operative week (p = 0.001 and 0.011 respectively) but no difference at 24th post-operative week (p = 0.313). The rate of hardware complications was significantly higher in K wire group (p = 0.001). No significant difference was noted in in the Knee society score and post-operative complications between the groups.

CONCLUSION

This study concludes that the fixation of closed transverse patella fractures using two 4.5 mm cannulated screws is allows a faster rate of union, a better knee range of motion and lesser hardware complications as compared to Kirschner wires. However more studies with larger sample sizes and longer follow up are required.

Comparison of minimally invasive percutaneous fixation and open reduction internal fixation for patella fractures: a meta-analysis

BACKGROUND

Open reduction internal fixation (ORIF) has long been the conventional procedure for managing displaced patella fracture. This surgical approach has certain drawbacks, which might affect clinical outcomes and patient prognosis. Minimally invasive percutaneous fixation (MIPF) was proposed to overcome these disadvantages. Few in-depth investigations have been performed to determine the superiority of MIPF over ORIF. The aim of this study was to compare the efficacies of MIPF and ORIF for patella fractures.

METHODS

The PubMed, Cochrane Library, Embase, and Scopus databases were searched for relevant studies from November 26 to December 17, 2020. Non-English publications and pediatric orthopedic articles were excluded. Statistical analysis was performed using Review Manager, version 5.4, with mean differences (MDs), standardized mean differences (SMDs), odds ratios (ORs), and respective 95% confidence intervals (CIs) calculated using a random effects model. The primary outcomes were the pain score, knee range of motion, and joint functionality. The secondary outcomes were the surgical time, complications, and implant removal rate.

RESULTS

Six articles with a total of 304 patients were included in the meta-analysis. Pooled analysis revealed that patients with MIPF had a significantly reduced pain score (MD = - 1.30, 95% CI = - 1.77 to -0.82; p < 0.00001) and increased knee extension angles (MD = 0.72, 95% CI = 0.18 to 1.25; p = 0.009) at 3-month follow-up. Furthermore, knee flexion angles (MD = 8.96, 95% CI = 5.81 to 12.1; p < 0.00001) and joint functionality (SMD = 0.54, 95% CI = 0.21 to 0.86; p = 0.001) had statistically improved at 2 years. However, no difference was observed between MIPF and ORIF with regard to the surgical time. The risk of complications (OR = 0.10, 95% CI = 0.05 to 0.18; p < 0.00001) and implant removal rate (OR = 0.20, 95% CI = 0.07 to 0.57; p = 0.003) were significantly lower with MIPF than with ORIF.

CONCLUSIONS

MIPF is more favorable than ORIF in terms of the pain score, knee range of motion, joint functionality, complications, and implant removal rate. Thus, it can be adopted as an alternative to ORIF.

Comparison of the Kirschner Wire Tension Band with a Novel Nickel-Titanium Arched Shape-Memory Alloy Connector in Transverse Patellar Fractures: A Retrospective Study

This study aims to compare the clinical outcomes of the nickel-titanium arched shape-memory alloy connector (hereafter referred to as the ASC) and tension band fixation for the treatment of transverse patellar fractures. We retrospectively analyzed a total of 257 patients with transverse patellar fractures who were treated at our emergency orthopaedics department from March 2010 to March 2017. Either an ASC or the Kirschner wire (K-wire) tension band had been used to treat these fractures according to surgeons' experience and preference. We compared operative details, postoperative recovery, and postoperative knee function at 6 months. In terms of surgical duration, blood loss, incision length, length of hospital stay, and postoperative complications, patients in the ASC group showed significantly better results than patients in the K-wire group (p < 0.05). There were no significant differences between the two groups in terms of fracture healing time, knee mobility, and the Boström score at the postoperative 6-month evaluation (p > 0.05). Though, there were similar functional outcomes between two groups whose transverse patellar fractures were different methods, we found that the ASC method was a more reliable, more minimally invasive, and safer treatment option than the tension band wiring method using K-wires, resulting in less tissue damage, shorter surgical duration, shorter length of hospital stay, and fewer complications.

Loop Anchor Tension Band Technique for Patella Fractures Lowers the Rate of Kirschner Migration

OBJECTIVE

To compare the complications of patella fracture after open reduction and internal fixation using our innovative, loop-based modification of the tension band wiring technique and the traditional tension band wiring technique.

METHODS

Fifty-eight patients with patella fracture (AO/OTA: 34-C) were enrolled in this retrospective case-control study during the study period. We treated 36 patients with the traditional tension band wiring and 22 patients with our loop anchor tension band technique. Lysholm knee scoring scale, sex, numbers of wire dislodge, number of implants removal between two groups were compared.

RESULTS

The number of cases of wire dislodgement was zero in the loop anchor tension band group and seven in the traditional tension band group. There was statistically significant difference (P = 0.037). Lysholm knee score (P = 0.685) and operation time (P = 0.395) were not significantly different between the two groups CONCLUSIONS: The loop anchor tension band technique is safe and effective for treating patella fractures. The rates of implant loosening and wire pull-out were significantly lower in the loop anchor tension band group than those in the traditional technique group.

Interventions for treating fractures of the patella in adults

BACKGROUND

Fractures of the patella (kneecap) account for around 1% of all human fractures. The treatment of these fractures can be surgical or conservative (such as immobilisation with a cast or brace). There are many different surgical and conservative interventions for treating fractures of the patella in adults. This is an update of a Cochrane Review first published in 2015.

OBJECTIVES

To assess the effects (benefits and harms) of interventions (surgical and conservative) for treating fractures of the patella in adults.

SEARCH METHODS

We searched CENTRAL (2020, Issue 1), MEDLINE, Embase, LILACS, trial registers and references lists of articles to January 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs that evaluated any surgical or conservative intervention for treating adults with fractures of the patella. The primary outcomes were patient-rated knee function, knee pain and major adverse outcomes.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected eligible trials, assessed risk of bias and cross-checked data extraction. Where appropriate, we pooled results of comparable trials.

MAIN RESULTS

We included 11 small trials involving 564 adults (aged 16 to 76 years) with patella fractures. There were 340 men and 212 women; the gender of 12 participants was not reported. Seven trials were conducted in China and one each in Finland, Mexico, Pakistan and Turkey. All 11 trials compared different surgical interventions for patella fractures. All trials had design flaws, such as lack of assessor blinding, which put them at high risk of bias, potentially limiting the reliability of their findings. No trial reported on health-related quality of life, return to previous activity or cosmetic appearance. The trials tested one of seven comparisons. In the following, we report those of the main outcomes for which evidence was available for the three most important comparisons. Four trials (174 participants) compared percutaneous osteosynthesis versus open surgery. Very low-quality evidence means that we are uncertain of the findings of no clinically important difference between the two interventions in patient-rated knee function at 12 months (1 study, 50 participants) or in knee pain at intermediate-term follow-up at eight weeks to three months. Furthermore, very low-quality evidence means we are uncertain whether, compared with open surgery, percutaneous fixation surgery reduces the incidence of major adverse outcomes, such as loss of reduction and hardware complications, or results in better observer-rated knee function scores. Two trials (112 participants) compared cable pin system (open or percutaneous surgery) versus tension band technique. The very low-quality evidence means we are uncertain of the findings at one year in favour of the cable pin system of slightly better patient-rated knee function, fewer adverse events and slightly better observer-rated measures of knee function. There was very low-quality evidence of little clinically important between-group difference in knee pain at three months. Very low-quality evidence from two small trials (47 participants) means that we are uncertain of the findings of little difference between biodegradable versus metallic implants at two-year follow-up in the numbers of participants with occasional knee pain, incurring adverse events or with reduced knee motion. There was very low-quality and incomplete evidence from single trials for four other comparisons. This means we are uncertain of the results of one trial (28 participants) that compared patellectomy with advancement of vastus medialis obliquus surgery with simple patellectomy; of one quasi-RCT (56 participants) that compared a new intraoperative reduction technique compared with a standard technique; of one quasi-RCT (65 participants) that compared a modified tension band technique versus the conventional AO tension band wiring (TBW) technique; and of one trial (57 participants) that compared adjustable patella claws and absorbable suture versus Kirschner wire tension band.

AUTHORS' CONCLUSIONS

There is very limited evidence from nine RCTs and two quasi-RCTs on the relative effects of different surgical interventions for treating fractures of the patella in adults. There is no evidence from trials evaluating the relative effects of surgical versus conservative treatment or different types of conservative interventions. Given the very low-quality evidence, we are uncertain whether methods of percutaneous osteosynthesis give better results than conventional open surgery; whether cable pin system (open or percutaneous surgery) gives better results than the tension band technique; and whether biodegradable implants are better than metallic implants for displaced patellar fractures. Further randomised trials are needed, but, to optimise research effort, these should be preceded by research that aims to identify priority questions.

A precise navigation device for fixation of patella fractures with modified K-wire tension band:a comparative retrospective study

Background

Traditionally, the technique of modified tension band wires (MTBW) has been the most commonly used surgical procedure. The purpose of this study is to design a precise navigation device that can obtain a standard position of K-wires for (MTBW) and to compare the precise MTBW (P-MTBW) by a navigation device with the conventional MTBW (C-MTBW) by hands in a retrospective study.

Methods

The device was designed by solidworks2012 software (USA), which could provide a precise guidance for obtaining parallel K-wires. Besides, it could set the distance between two K-wires and the level of K-wires below patellar anterior surface. From June 2014 to August 2018, a total of 112 patients were employed in this retrospective study. The patients were divided into P-MTBW group and C-MTBW group according to the surgical technique with or without the precise navigation device. We needed to record and analyze the operation time and the number of fluoroscopy, postoperative internal fixation imaging, knee function and complications.

Results

There were 54 patients in P-MTBW group and 58 patients in C-MTBW group. There were statistically significant differences (P < 0.001) in the operation time between P-MTBW group (39.5 ± 4.7; range, 32–49 min) and C-MTBW group (53.7 ± 6.8; range, 42–71 min). The number of intraoperative fluoroscopy was significantly less (P < 0.001) in P-MTBW group (4.2 ± 1.4) versus that of C-MTBW group (8.3 ± 2.7). According to Iowa knee score, there was no significant difference (P = 0.268 at 1 year) in function between the two groups. According to our own evaluation criteria for MTBW, anyone in the P-MTBW group was excellent and 26 patients were excellent, 20 patients were good, and 2 patients were fair in the C-MTBW group.

Conclusion

The navigation device can reduce operation time and intraoperative fluoroscopy frequency. P-MTBW fixation is an accurate and effective surgical procedure for patella fractures.

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.

Comparison of the Therapeutic Effects of Tension Band with Cannulated Screw and Tension Band with Kirschner Wire on Patella Fracture

Background

Patella fracture accounts for 1% of bone injury, of which anatomical reduction is of great significance to the recovery. Tension band with cannulated screw and Kirschner wire is commonly used methods for the treatment of displaced patella fracture. However, there is still some controversy on the clinical efficacy of the two treatment methods.

Objective

This study aimed at comparing the therapeutic effects of the cannulated screw and Kirschner wire tension bands on patella fracture and at providing more data basis for clinical selection of treatment methods for patella fracture.

Methods

Altogether, 146 patients with displaced patella fracture admitted to our hospital from March 2016 to February 2018 were selected and divided into two groups according to the different treatment methods. Among them, 71 patients received tension band with a cannulated screw (TBWCS group) and 75 patients received tension band with Kirschner wire (TBWKW group). Two groups of patients were compared in terms of surgical treatment effect after one year of treatment, complications within six months after the operation and operation-related indexes. The pain visual analogue scale (VAS) score, knee flexion degree, Lysholm score, and Bostman score were recorded at 1, 3, 6, and 12 months after operation, and the activity of daily living scale (ADL) score was evaluated at the last follow-up.

Results

During the operation of patella fracture patients, the intraoperative blood loss, hospitalization time, and knee flexion loss of patients in TBWCS group were less than those in the TBWKW group (P < 0.05), the starting time of postoperative functional exercise was earlier than that of patients in TBWKW group (P < 0.05), and the incidence rate of secondary operation was lower than that of patients in the TBWKW group (P < 0.05), but there was no statistical difference in the operation time, incision length, and postoperative fracture gap between the two groups. The results of curative effect analysis showed that the knee flexion, Lysholm score, and Bostman score of patients treated with tension band with cannulated screw were higher than those treated with Kirschner wire (P < 0.05), and VAS score was lower. Tension band with cannulated screw had a better curative effect on patella fracture (P < 0.05), lower complication rate (P < 0.05), and higher quality of life of patients (P < 0.05).

Conclusion

Tension band with cannulated screw has a good curative effect on patella fracture, low incidence of complications, early start of postoperative functional exercise, and high quality of life.

Nonhardware Subchondral Transosseous Cerclage for Displaced Comminuted Patella Fracture Repair: A Case Report

CASE

We report a case of a 62-year-old woman who presented to our clinic with a displaced transverse comminuted patella fracture. The fracture was repaired using a subchondral transosseous suture cerclage technique which uses the dense subchondral bone to obtain an initial anatomic reduction of the articular surface, contain the comminution, and achieve union while avoiding complications associated with traditional hardware.

CONCLUSION

This case illustrates the potential for the broader implementation of subchondral transosseous cerclage suture fixation techniques for 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.

[Patellar fractures]

Patellar fractures are a relatively rare entity with an prevalence of 1%. Preoperative computed tomography has gained a significant role as a diagnostic tool for patellar fractures in recent years. It enables an exact assessment of the fracture and helps in the decision making for the correct treatment procedure. Therapeutically, the armamentarium was supplemented by angle stable plate fixation, which potentially enables a better reconstruction of the patella than the conventional tension band fixation. In this context, the results of angle stable plate fixation are promising in terms of functional outcome and lower complication rates. The proven tension band fixation using K‑wires or cannulated screws continues to be widespread in clinical practice and retains significance for simple patellar fractures. The use of polyethylene thread material instead of steel wire has shown advantages in biomechanical studies but the clinical application is more restrained.

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.

[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.

Treatment of Patella Fractures

Patella fractures comprise 1% of all fractures. Treatment options vary based on fracture displacement, classification, and patient factors. Traditionally, nonoperative treatment has been reserved for nondisplaced fractures. Many operative treatments are available with differing indications and levels of success. Tension band constructs have been the most commonly employed approach to fixation, with cerclage wiring for comminuted fractures. Recently, plate fixation of patella fractures has become more popular. Plating constructs offer a low-profile design with stable fixation, allowing for earlier mobilization and potentially improved functional outcomes. Data regarding the long-term outcomes of plating techniques are limited, and further studies are needed. [Orthopedics. 2018; 41(6):e747-e755.].

Efficacy of K-wire tension band fixation compared with other alternatives for patella fractures: a meta-analysis

Background

To compare the efficacy and safety of K-wire tension band fixation (KTB) with other alternative approaches (cannulated screws, cable pin, and ring pin) for treatment of patella fractures by performing a meta-analysis.

Methods

PubMed and EMBASE databases were searched for all relevant studies. Standardized mean difference (SMD) or relative risk (RR) and their corresponding 95% confidence intervals (CIs) were calculated for continuous or dichotomous outcomes via either a fixed- or random-effect model using Stata 13.0 software.

Results

Nine literatures involving 949 patients (581 in the KTB group and 368 in the control group) were included. Pooled analysis showed there were no differences in the success rate, operative time, healing time, and number of infections between patients undergoing KTB and others. However, the incidence of complications (RR = 8.04, 95% CI = 4.45–14.53; p < 0.001) and VAS (SMD = 0.642, 95% CI = 0.22–1.06; p = 0.003) were lower, while flexion degree (SMD = − 0.70 95% CI = − 1.04–− 0.36; p < 0.001), Böstman joint function score (SMD = − 0.68, 95% CI = − 1.10–− 0.27; p = 0.001), Iowa knee score (RR = 0.88, 95% CI = 0.81–0.96; p = 0.004), and Lysholm score (SMD = − 0.71, 95% CI = − 1.10–− 0.32; p < 0.001) were significantly higher in patients undergoing alternative approaches than the KTB. Subgroup analysis also demonstrated the cannulated screw fixation was superior to KTB in reducing the incidence of complications.

Conclusions

Alternative treatments may be effective for management of patella fractures and should be attempted to be popularized in clinic.

Treatment of displaced transverse fractures of the patella: modified tension band wiring technique with or without augmented circumferential cerclage wire fixation

BACKGROUND

Displaced transverse fractures of the body of the patella are usually associated with disruption of extensor mechanism and should be fixed surgically. The most common method is a tension band wiring (TBW) technique. Some surgeons concurrently employ an augmented circumferential cerclage wiring (ACCW) technique to help fracture stabilization and aid in fracture healing; however, its role and effect on the treatment outcomes is unclear.

METHODS

We performed a STROBE-compliant retrospective observational cohort study on all cases of acute closed patella fracture that were treated at our institution between 2006 and 2012. Of 185 episodes, 72 (38.9%) were eligible for this study according to our inclusion/exclusion criteria. We classified these subjects with AO/OTA type 34-C1.1 or 34-C2 lesions into two groups for analyses: fractures treated with modified TBW and ACCW (group 1, n = 27) and those treated with modified TBW alone (group 2, n = 45). Plain radiographs were used to evaluate radiographic outcomes and the effect of potential risk factors on fixation failure was analyzed by subgroup comparisons.

RESULTS

Our results revealed that there were no significant differences in the rates of fixation failure (P = 0.620), nonunion (P = 0.620), and revision surgery (P = 0.620) between the groups. Although not statistically significant, there was a trend towards a positive risk association between fixation failure and age distribution > 60 years (10.0% vs. 0.0%, P = 0.124; OR = 8.0, P = 0.168) and > 70 years (9.4% vs. 2.5%, P = 0.321; OR = 4.0, P = 0.237) and the superficial level of the K-wires (12.0% vs. 1.5%, P = 0.117; OR = 6.3, P = 0.121). Regarding those modified TBW patients concurrently treated with an ACCW, the potential risk association between fixation failure and the superficial level of the K-wire was prone to increase further (28.6% vs. 0.0%, P = 0.060; OR = 18.6, P = 0.071).

CONCLUSIONS

Concurrent application of an ACCW might be needless and not efficacious to help fracture stabilization and healing in patients having been treated with modified TBW for displaced transverse fractures of the body of the patella. Adherence to correct surgical technique such as putting the K-wires at the proper level and securing control of the both ends of the K-wires may be more important and help in improving outcomes.

Modified Technique of Separate Vertical Wiring for the Fixation of Patellar Inferior Pole Fracture

To evaluate the biomechanical and clinical results of modified separate vertical wiring technique (SVW) for inferior pole patellar fracture repair we conducted a finite element biomechanical study using 2 fixation methods and evaluated a clinical series of eleven patients. The modified SVW technique was an effective, safe and simple method that can provide stable fixation for early exercise with excellent functional results in fixing inferior pole patella fractures.

Definition of infection after fracture fixation: A systematic review of randomized controlled trials to evaluate current practice

INTRODUCTION

One of the most challenging musculoskeletal complications in modern trauma surgery is infection after fracture fixation (IAFF). Although infections are clinically obvious in many cases, a clear definition of the term IAFF is crucial, not only for the evaluation of published research data but also for the establishment of uniform treatment concepts. The aim of this systematic review was to identify the definitions used in the scientific literature to describe infectious complications after internal fixation of fractures. The hypothesis of this study was that the majority of fracture-related literature do not define IAFF.

MATERIAL AND METHODS

A comprehensive search was performed in Embase, Cochrane, Google Scholar, Medline (OvidSP), PubMed publisher and Web-of-Science for randomized controlled trials (RCTs) on fracture fixation. Data were collected on the definition of infectious complications after fracture fixation used in each study. Study selection was accomplished through two phases. During the first phase, titles and abstracts were reviewed for relevance, and the full texts of relevant articles were obtained. During the second phase, full-text articles were reviewed. All definitions were literally extracted and collected in a database. Then, a classification was designed to rate the quality of the description of IAFF.

RESULTS

A total of 100 RCT's were identified in the search. Of 100 studies, only two (2%) cited a validated definition to describe IAFF. In 28 (28%) RCTs, the authors used a self-designed definition. In the other 70 RCTs, (70%) there was no description of a definition in the Methods section, although all of the articles described infections as an outcome parameter in the Results section.

CONCLUSION

This systematic review shows that IAFF is not defined in a large majority of the fracture-related literature. To our knowledge, this is the first study conducted with the objective to explore this important issue. The lack of a consensus definition remains a problem in current orthopedic trauma research and treatment and this void should be addressed in the near future.

Biomechanical evaluation of simulated feline patellar fracture repairs

Objective: To investigate four techniques for stabilization of feline patellar fracture.

Methods: Feline cadaveric stifles with simulated patellar fracture were stabilized with one of four techniques: Group A - circumferential wire, group B - figure-of-eight wire, group C - combined figure-of-eight and circumferential wire, group D - pin and tension band wire. All repairs were subjected to a period of cyclic loading prior to load to failure testing. Experiments were recorded by video capture to determine load at failure and failure mode. Failure was defined as an opening of the fracture gap of 3 mm.

Results: Mean fracture gap opening (±SD) during peak loading after 1000 cycles was: group A with 1.66 mm (± 0.69), group B with 1.01 mm (± 0.45), group C with 0.81 mm (± 0.58), and group D with 0.65 mm (± 0.54). Groups C and D had significantly lower mean fracture gap opening after 1000 cycles when compared to group A (p <0.05). Mean loads (± SD) at failure were: group A with 171.4 N (± 62.2), group B with 208.7 N (± 20.7), group C with 288.2 N (± 62.5), and group D with 219.5 N (± 48.0). Group C had significantly higher mean load to failure than all other groups (p <0.05). There was no difference between other groups. In groups A, B and C the principle mode of failure was wire elongation and tearing of sutures through the retinaculae and periarticular soft tissues. In group D, the principle mode of failure was the pin pulling through the bone of the distal fragment.

Conclusions: Combined figure-of-eight and circumferential wires may be useful for treatment of transverse feline patellar fracture.

Functional outcome and economic burden of operative management of patellar fractures: the pivotal role of onerous implants

OBJECTIVES

The complication rate following operative treatment of patellar fractures remains high and is associated with a poor functional outcome. The primary goal of this study was to evaluate our functional outcome of patellar fracture osteosynthesis and define strategies to improve the outcome. The healthcare costs and utilization were calculated.

METHODS

All demographic, clinical, radiographic variables and hospital-related costs of 111 patients with 113 surgically treated patellar fractures between January 2005 and December 2014 were analyzed. Fractures were grouped as either simple or complex. Functional outcome was assessed using Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

There were 67 simple fractures (59.3%) and 46 complex fractures (40.7%). The overall complication rate was 48.7%, including 19.5% implant-related complications. In 69 patients (61.1%), implants were removed. The outcome was rather poor, with considerable impairment in all KOOS subscales with the knee-related quality of life rated worst (median 62.5, IQR 37.5-81.25). Poor outcome correlated significantly with complex patellar fractures and extensive tension-band constructs.

CONCLUSIONS

The operative treatment of patellar fractures was associated with a high complication rate, functional impairment and reduced quality of life. Complex patellar fractures and extensive tension-band constructs were identified as the main determinants of poor outcome and increased economic burden due to higher reinterventions rates. Strategies to reduce complications and improve outcome should focus on less onerous implants.

Clinical results of treatment using a modified K-wire tension band versus a cannulated screw tension band in transverse patella fractures: A strobe-compliant retrospective observational study

It was a retrospective case-control study. The aim of this study was to explore the clinical efficacy and complication of treatment using a modified Kirschner wire tension band (MKTB) or a cannulated screw tension band (CSTB) in transverse patellar fractures.In total, 55 patients with transverse patellar fractures were retrospectively reviewed and divided into 2 groups according to the surgical technique: 29 patients were in the MKTB group and 26 patients in the CSTB group. B[Latin Small Letter o with Caron]stman's clinical grading scale, including range of movement (ROM), pain, ability to work, atrophy of quadriceps femoris, assistance in walking, effusion, giving way, and stair-climbing, was used to evaluate the clinical results. Complications including painful hardware, implant loosening or breakage, and bone nonunion were also assessed.Both groups were evaluated at the final follow-up before removing implant in the MKTB group. The B[Latin Small Letter o with Caron]stman's score of ROM, pain, atrophy of quadriceps femoris, and effusion were all higher in the CSTB group than in the MKTB group (P < 0.05). Twelve patients in the MKTB group underwent implant removal, and the score of ROM, pain, and effusion were higher than before removing implant (P < 0.05), but there was no difference compared to the CSTB group (P > 0.05). Seventeen patients achieved excellent results, 9 had good results, and 3 reported fair results in the MKTB group; the CSTB group had excellent results in 22 patients and good results in 4 patients, showing a significant difference in the excellent rate between the 2 groups (P = 0.021). Total B[Latin Small Letter o with Caron]stman scores in the MKTB and CSTB groups (26.96 ± 4.47 and 29.42 ± 1.47, respectively) were significantly different (P = 0.01). Total scores in the MKTB group after removing implant were higher than those before removing implant (P = 0.001), and similar to those in the CSTB group (P = 0.224). Eleven patients in the MKTB group reported painful hardware, including 4 cases of implant loosening.CSTB achieves better clinical results than MKTB, meanwhile avoiding the problems of painful hardware and implant loosening. Functional limitation caused by hardware pain was commonly seen in the MKTB group, and removing implant after fracture healing improved knee function.