[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.

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

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

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.

Incidence and types of preceding and subsequent fractures in cats with patellar fracture and dental anomaly syndrome

OBJECTIVES

The aim of this study was to document the incidence of preceding and subsequent fractures to the patellar fractures in cats with patellar fractures and dental anomaly syndrome.

METHODS

Records of cats with patellar fracture and dental anomaly syndrome were retrieved from the combined databases at the University of Bristol, UK, and Exclusively Cats Veterinary Hospital, USA. A request was made to complete a questionnaire to obtain long-term follow-up of these cats with respect to their current status and fractures to other bones; radiographs and histories were requested and were reviewed for treatment of ongoing fractures and outcome.

RESULTS

Of the 191 cases reported with this syndrome, 92 cats (48.2%) had dental anomalies and 78 (40.8%) had fractures to other bones; 21 cats sustained the fractures preceding the patellar fractures and 57 subsequently. In total, there were 175 fractures: acetabulum (25%), tibia (22%), ischium (15.4%), humeral condyle (13.7%), calcaneus (5.1%), ilium (5.1%), pubis (3.4%) and other bones (10.2%). The majority of these fractures were characteristic of insufficiency (stress) fractures with a very similar configuration in each bone.

CONCLUSIONS AND RELEVANCE

A high proportion of cats with patellar fracture and dental anomaly syndrome will have preceding or subsequent fractures to their patellar fractures. In this study, >10% of cats suffered characteristic fractures preceding the patellar fractures. The presence of these fractures should alert the veterinarian to the possibility that the cat is affected by patellar fracture and dental anomaly syndrome.

Skull pathology in 10 cats with patellar fracture and dental anomaly syndrome

CASE SERIES SUMMARY

The aim of this case series is to describe the clinical and radiological features of mandibular and maxillary abnormalities in cats diagnosed with patellar fractures and dental anomalies, a condition that we have named 'patellar fracture and dental anomaly syndrome' (PADS), also known previously as 'knees and teeth syndrome'. Where available, clinical records, skull and/or intraoral dental radiographs, head CT images, microbiology and histopathology reports were collected, and follow-up was obtained. Ten cats with mandibular or maxillary abnormalities were identified. Common clinical features included multiple persistent deciduous teeth, gingivitis and swellings of the jaw. Skull radiographs were available for 7/10 cats and head CT images were available for one cat. Findings included marked bony and periosteal proliferation, hypodontia, root resorption, root malformation and unerupted permanent teeth. Where available, microbiology and histopathology results were consistent with osteomyelitis.

RELEVANCE AND NOVEL INFORMATION

Mandibular and maxillary abnormalities are an additional unreported clinical feature of the rare condition that we have termed PADS. Radiologically, these lesions can have an aggressive appearance, which can mimic neoplasia. Medical management with antibiotic and anti-inflammatory therapy improves clinical signs in the short term; however, surgical extraction of persistent deciduous and unerupted permanent teeth, and debridement of proliferative and necrotic bone appear to be necessary for an improved outcome. Additional information on long-term outcome is required.

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.