Fixation of patella fractures with a minimally invasive tensioned wire method: Compressive external fixation

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.

Comparison of double-strand braided polyester sutures tension band (Nice knot) with cable tension band in transverse patellar fractures

BACKGROUND

The tension band technique is the most common method for internal fixation of transverse patellar fractures. Titanium cable and high-strength sutures have been successfully applied in this treatment; however, few studies have compared the Nice knot technique using sutures with the standard cable technique. Whether the suture technique (Nice knot) provides preferable results compared with those of the cable technique is unclear.

METHODS

Forty patients with transverse patellar fractures participated in this study. Twenty patients underwent sutures tension band fixation (Nice knot), and the others were managed with cable tension bands. All patients were followed up at 1, 3, 6, and 12 months. Pain was measured by VAS scores, flexion and extension of the knee were measured in degrees by goniometry, and knee function was evaluated using the Böstman clinical grading scale.

RESULTS

The two groups had equal distributions in age, gender, injured side, and fracture classification. The mean operation time in the suture group was shorter (55.75±9.77 minutes versus 64.25±9.63 minutes). The VAS score was comparable in the two groups at the 1-month, 3-month, and 6-month follow-ups; however, the score was lower at 12 months postoperatively in the suture group (P=0.037). No significant difference was found in flexion, extension, Böstman score, or fracture healing time in either group (P>0.05). Postoperative complications were higher in the cable group (9 versus 2) (P = 0.031) but were mostly related to symptomatic soft tissue irritation.

CONCLUSION

The suture tension band technique using braided polyester nonabsorbable sutures tied with Nice knot was as effective as the cable tension band technique for transverse patellar fracture management. However, more convenient operations, less cost and fewer complications were found in suture fixation (Nice knot).

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.

Patella fracture fixation with a non-locked anterior plating technique: A biomechanical study

OBJECTIVES

The purpose of this study was to compare the biomechanical attributes of patella fracture fixation with either anterior plating utilizing two parallel, longitudinal 2.0 mm plates technique versus a cannulated screw tension band technique.

METHODS

Five matched pairs (ten specimens) of fresh frozen cadavers were utilized. A transverse patella fracture (OTA 34C1.1) was fixed using either two 4.0 mm cannulated screw anterior tension band (CATB) or with two 2.0 mm stainless steel non-locking plates along the anterior cortex secured with 2.4 mm cortical screws traversing the fracture site. Specimens underwent 1000 cycles of simulated active knee range of motion before load to failure destructive testing.

RESULTS

During cyclic loading there were no failures in the plate fixation group, and 2 out of 5 specimens catastrophically failed in the CATB group (p = 0.22). Average fracture displacement at the end of fatigue testing was 0.96 mm in the plate fixation group and 2.72 mm in the CATB group (p = 0.18). The specimens that withstood cyclic testing underwent a destructive load. Mean load to failure for the plate fixation specimens was 1286 N, which was not significantly different from the CATB group mean of 1175 N (p = 0.48). The mechanism of failure in the plate fixation cohort was uniformly via a secondary vertical patella fracture around the plates in all five specimens. In the CATB group, the mechanism of failure was via wire elongation and backing out of the screws.

CONCLUSIONS

Patella fixation with anterior plating technique statistically performed equivalent to cannulated screw anterior tension band in ultimate load to failure strength and fatigue endurance under cyclical loading. No failures were observed cyclic simulated active range of motion in the anterior plate group. There was a trend towards improved fatigue endurance in the plate fixation group, however this did not reach statistical significance. We believe plate fixation technique represents a low-profile implant option for treatment of transverse patella fractures, which may allow for early active range of motion, and these data support biomechanical equivalency to standard of care.

Percutaneous cerclage wiring for type 34-C patella fracture in geriatric patients

PURPOSE

This study was to retrospectively evaluate clinical outcomes of geriatric patients with patella fracture treated by percutaneous cerclage wiring and to introduce the surgical technique.

METHODS

From January 2009 to December 2015, fifty-seven consecutive geriatric patients of type 34-C patellar fracture underwent closed reduction and percutaneous cerclage wiring fixation in our hospital. Visual Analog Scale (VAS) score, Levack score system, WOMAC test form of pain, stiffness and function, and knee joint range of motion (ROM) were applied for functional evaluation.

RESULTS

Fifty-three patients were followed up for a mean period of 36 months (12 to 82 months). All fractures were unioned, no wound infection, second displacement of fracture fragment or wire migration was found. Wire breakage happened in one case at six months post-operation. Thirteen patients had hardware removed, nine cases for implant irritation at the knot and four cases for no specific reason. No patient developed postoperative knee stiffness, and range of motion was 128.6° (110-140). The average VAS score of emotional knee function was 87.5 (65-99) preinjury and 78.1 (53-95) at the last follow-up. 86.8% (46/53) patients considered that they regained more than 80% of their knee function. The average Levack score was 10.0 (6-12), which included thirty-five evaluations of "excellent" and eighteen of "good". The average WOMAC score was 21.3 (13-37).

CONCLUSIONS

Percutaneous cerclage wiring fixation is a viable option for type 34-C patella fracture in geriatric patients.

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.].

Staged treatment of a chronic patellar sleeve fracture using the Taylor spatial frame

Patellar sleeve fractures are easily missed injuries since plain radiographs may not show a bony fragment at the time of injury. Failure to diagnose these injuries can result in patellar instability, extensor lag, and anterior knee pain. We report a novel treatment using a Taylor spatial frame as part of a staged reconstruction to regain length of the extensor mechanism and maintain knee motion prior to performing primary repair of the avulsed patellar sleeve fragment. In our case, an 11-year-old male presented to our institution six months after sustaining a patellar sleeve fracture. Radiographic examination with the knee in extension revealed a 23-mm gap between the inferior patellar pole fragment and the remaining patella. The patient was ultimately taken to the operating room twelve months after the initial injury for placement of a Taylor spatial frame to regain length of the extensor mechanism. The patient began immediate knee range-of-motion exercises, and performed daily soft tissue lengthening of two millimeters. After four weeks of treatment the patient underwent removal of the fixator and primary repair of the patella. At final follow up six years after patellar reconstruction, the patient had an active knee range-of-motion from five degrees of hyperextension to 140° of flexion. Where current literature reports suboptimal results even when treatment is delayed for two months, in our case the patient was able to obtain a high level of function after treatment with a two-stage reconstruction using a Taylor spatial frame.

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

BACKGROUND

K wire fixation with tension band wiring has conventionally been used for the open reduction and internal fixation of the patella. However, it suffers from distinct disadvantages such as implant irritation, need for open reduction, incidence of palpable implants, and need for subsequent implant removal. A smaller incision with percutaneous fixation may be an alternative to this established conventional technique. Thus, the purpose of this trial was to compare the treatment outcomes of patients with mildly displaced patellar fractures treated with closed reduction and percutaneous cannulated screw fixation (CRCF) as compared to open reduction and tension band wiring fixation (ORTF). Specifically, we aimed to determine whether cannulated screw fixation was associated with improved clinical outcomes at 12 months as measured using the Lysholm score, pain scores, degree of flexion, range of motion, time to radiographic union, radiographic outcomes, and complication rates.

METHODS

Sixty-three patients with transverse patellar fractures displaced less than 8 mm were included in this prospective, randomized, controlled trial, with 52 patients in the final data analysis. Thirty-two patients were operatively treated by CRCF with either two or three cannulated screws. Thirty-one patients were operatively treated by conventional ORTF using the modified tension band technique. At postoperative intervals of 3, 6, and 12 months, knee function was evaluated using the Lysholm score, pain was assessed using the visual analog scale (VAS) score, and active knee extensions and flexion were measured in degrees by goniometry.

RESULTS

The CRCF group had average Lysholm scores of 84.4 ± 5.8, 86.7 ± 6.4, and 93.2 ± 5.3 after 3, 6, and 12 months, respectively, which were significantly greater than those of the ORTF group (79.0 ± 5.3, p = 0.001; 81.5 ± 4.6, p = 0.002; and 89.8 ± 6.2, p = 0.039, respectively). Lower pain and squatting scores were the main reasons for the poorer Lysholm scores in the ORTF group. The VAS scores showed that the CRCF group had lower pain scores and better flexion and total range of motion (ROM) compared with the ORTF group after 3 and 6 months, although both groups had similar outcomes after 12 months. The mean fracture healing time of 2.65 months was similar in the CRCF groups (2.77 months; p = 0.440). Complication rates were 3/26 (11.5 %) in the CRCF group and 14/26 (53.4 %) in the ORTF group. Two patients in the CRCF group and eight patients in the ORTF group experienced skin irritation. In addition, two (7.7 %) patients in the CRCF group and 11 (42.3 %) patients in the ORTF group required implant removal because of symptoms due to the presence of the implants.

CONCLUSION

Surgical treatment of mild displaced (less than 8 mm) transverse patellar fractures by the CRCF technique provides satisfactory clinical results and excellent knee function, with little pain and a low incidence of complications at early follow-up (up to 6 months). These results suggest that the CRCF technique may be a superior alternative to conventional ORTF. Registration Trial (Chinese Clinical Trial Register): Current Controlled Trials ChiCTR-PRCH-14005017, registration dates 2014-06-14.

Current Treatment Strategies for Patella Fractures

Patella fractures can be caused by excessive tension through the extensor mechanism or a direct impact. Non-displaced fractures with an intact extensor mechanism can be treated nonoperatively. Surgical treatment is recommended for fractures that either disrupt the extensor mechanism or have greater than 2 to 3 mm of step-off and greater than 1 to 4 mm of displacement. Tension band fixation is the most commonly employed surgical technique; however, this can be technically demanding, especially in multifragmentary fractures. Symptomatic hardware is the most common complication following operative treatment. Functional impairment remains common after treatment of patella fractures. The purpose of this article is to review current treatment strategies to help optimize the management of patients with such patella fractures.

Comparison of the cable pin system with conventional open surgery for transverse patella fractures

BACKGROUND

The cable pin system is an effective device for fixation of transverse patella fractures. However, whether this device provides superior results using a minimally invasive technique instead of conventional open surgery using the K wire tension band method is unclear.

QUESTIONS/PURPOSES

We asked whether a minimally invasive technique would be associated with (1) increased operative time; (2) reduced postoperative pain; (3) faster recovery of ROM; (4) higher knee scores; and (5) reduced complications.

METHODS

Forty patients with displaced transverse fractures of the patella participated in this prospective, randomized, controlled trial. Twenty of these patients underwent a minimally invasive technique and the others had conventional open surgery using K wires. Some data for six of the 20 patients who underwent the minimally invasive technique were published in an earlier prospective, observational trial. At postoperative intervals of 1, 3, 6, 12, and 24 months, pain was measured by VAS scores, active flexion and extension of the knee were measured in degrees by goniometry, and knee function was evaluated using the Böstman clinical grading scale.

RESULTS

Operative time was longer in the minimally invasive surgery group (54.3 ± 9.8 minutes versus 48.5 ± 6.1 minutes). Pain scores were better (lower) in the minimally invasive surgery group at 1 and 3 months but not at 6 months. Early flexion, ultimate flexion, and knee scores from 3 to 24 months, likewise, were better in the minimally invasive surgery group. Complications mostly related to symptomatic hardware were less common in the minimally invasive surgery group.

CONCLUSIONS

The minimally invasive technique is superior to conventional open surgery using K wires in terms of less early postoperative pain, better mobility angles of the injured knee, higher functional score of the injured knee, and decreased incidence of complications.

LEVEL OF EVIDENCE

Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.