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

What Factors Are Associated With Patella Baja After Internal Fixation of Patellar Fractures?

BACKGROUND

Patellar fractures represent approximately 0.5% to 1.5% of all trauma-related fractures, and patella baja, or an abnormally low-lying patella, may be a result of treatment. This complication is underappreciated, and although patella baja may result in patient discomfort, stiffness, and later degenerative changes, the association between fracture type, operative treatment, and this complication is not well described.

QUESTIONS/PURPOSES

(1) What percentage of patients treated surgically for patellar fractures developed patella baja, and which fracture patterns were more likely to demonstrate postoperative patella baja? (2) What was the association between postoperative patella baja and functional outcomes as measured by ROM and Böstman score? (3) What complications were associated with the development of patella baja?

METHODS

Between January 2018 and January 2021, we treated 3244 patients for patellar fractures at the National Center for Orthopaedics in Shanghai, PR China. The average age of the patients was 53.4 ± 12.0 years, and the male-to-female ratio was 1:1.34. After accounting for exclusion and inclusion criteria, 11% (259 of 2370) of patients were lost to follow-up before 2 years, leaving 2111 patients for review in this retrospective study at a mean of 32 ± 9 months after injury. During this time, we generally recommended surgery for patellar fractures when the fracture demonstrated an articular surface step-off exceeding 2 mm or there was loss of knee extension function. According to the AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association) classification systems, the fractures were divided into eight subtypes: A1, B1, B2, C1.1, C1.2, C1.3, C2, and C3. All of these patients had CT scans and clinical data collected in our longitudinally maintained institutional database. Two independent observers classified the fractures based on the preoperative CT scan and recorded the Insall-Salvati index (ISI) on plain radiographs at the 2-year follow-up visit. An ISI of < 0.8 determined the presence of patella baja. Patient demographics, ROM, Böstman functional scores, complications, and implant removal rates were assessed. Binary logistic regression and linear regression models were employed to analyze risk factors for patella baja, associations, and treatment outcomes. Under the AO/OTA classification, the most common fracture patterns were C1.1 (30% [634 of 2111]) and C3 (25% [538 of 2111]).

RESULTS

Overall, 25% (527 of 2111) of patients had postoperative patella baja, and those with type A1 (OR 6.44 [95% confidence interval (CI) 4.57 to 9.10]), C1.3 (OR 4.96 [95% CI 3.68 to 7.10]), and C3 (OR 2.61 [95% CI 1.93 to 3.52]) fractures displayed a higher odds of developing patella baja. Patients with patella baja had poorer ROM in flexion than did patients without patella baja (116° ± 12° versus 125° ± 11° [95% CI 8.17° to 10.41°]; p < 0.01), and patients with patella baja did not have poorer Böstman scores at minimum 2-year follow-up (26.0 ± 3.2 versus 26.0 ± 3.2; p = 0.90). After controlling for potentially confounding variables such as sex, age, BMI, fracture classification, and complications, we found that fracture classification-specifically A1 (OR 6.7 [95% CI 4.8 to 9.5]), C1.3 (OR 5.0 [95% CI 3.6 to 6.9]), and C3 (OR 2.5 [95% CI 1.9 to 3.4])-deep infection (OR 10.5 [95% CI 4.2 to 26.5]; p < 0.001), and superficial infection (OR 2.4 [95% CI 1.4 to 4.4]; p = 0.003) were associated with the development of postoperative patella baja, whereas sex, BMI, and age were not. Postoperative infection was the only complication associated with patella baja.

CONCLUSION

The findings of this study underscore the importance for surgeons to be vigilant about the occurrence of patella baja after patellar fractures. In cases of the specific fracture types identified here, surgeons are encouraged to actively explore and adopt more suitable internal fixation techniques. By doing so, the incidence of postoperative patella baja may be effectively reduced, leading to better ROM and functional outcomes for patients.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Complications following surgical treatment of patella fractures - a systematic review and proportional meta-analysis

PURPOSE

The aim of this systematic review and proportional meta-analysis was to identify complications of surgical treatment of patella fractures and to estimate their incidence. We extended existing knowledge on this topic by including several more recent and large-scale studies.

METHODS

This systematic review and meta-analysis were performed in accordance with the Cochrane Handbook for systematic reviews of interventions. After searching in PubMed, MEDLINE, EMBASE, Cochrane Library, and OpenGrey, all studies after 2000, with study populations > 100 patients, including only patients > 18 years and follow-up > 30 days, were included. Two independent authors assessed the literature search and extracted the data. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. The meta-analysis was performed on complications pooled in infections, nonunion, symptomatic implant removal, and fixation failure.

RESULTS

The data on complications were available from 14 studies, including a pool of 5659 patients. The most common complication was symptomatic implant removal, affecting.

CONCLUSION

Surgically, treatment of patella fractures was associated with a high risk of complications. The most common complication was symptomatic implant removal, affecting 29.6% of patients. Other complications stated were fixation failure 5.2%, infections 3.1% and nonunion 1.7%.

Comparative study of wound outcomes and surgical strategies: Internal fixation versus external stabilization in rib fracture patients with traumatic chest wounds

The clinical management of traumatic chest incisions accompanied by rib fractures presents the formidable challenge. The study was carried out to compare the outcomes of auscultatory triangle internal fixation (ATIF) and external fixation (EF) in such injuries. From June 2019 to June 2022, 105 patients with multiple rib fractures participated in the cohort study in which they were divided into two groups: 53 patients underwent ATIF and 52 patients underwent EF. The incidence of surgical site infection, wound healing time, incidence of wound dehiscence, number of dressing changes, pain as measured by the visual analogue scale (VAS), duration of hospitalization, period of return to work, pulmonary complications and functionality of the upper limbs as assessed by the Disability of Arm, Shoulder, and Hand (DASH) questionnaire were among the parameters evaluated. In comparison with EF, ATIF demonstrated the decreased incidence of wound dehiscence (1.9% vs. 9.6%) (p < 0.05), surgical site infection (3.8 vs. 11.5) and wound healing time (12.3 ± 2.1 vs. 18.5 ± 3.7 days) (p < 0.05). Furthermore, during their ATIF treatment, patients required fewer changes of dressing (3.5 ± 0.8 vs. 5.7 ± 1.2) and demonstrated enhanced pain management, reduced hospital stays and expedited return to work (p < 0.05). ATIF group demonstrated enhancements in both upper limb functionality and post-operative pulmonary function (p < 0.05). The utilization of ATIF as opposed to EF for the treatment of traumatic chest wounds accompanied by rib fractures yields superior outcomes in terms of wound healing, infection reduction and restoration of pulmonary and upper limb functionality.

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.

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.

Arthroscopically Assisted, Minimally Invasive Percutaneous Fixation of a Patellar Fracture

Operative fixation of a patellar fracture can be accomplished through a variety of techniques. However, drawbacks have been associated with many of these techniques, including painful hardware, poor skin healing due to bruising and swelling, inadequate cartilage reduction, and eventual post-traumatic osteoarthritis. Throughout the orthopaedic field, minimally invasive approaches have become popular. We describe an arthroscopically assisted method for ensuring fracture reduction intraoperatively and addressing associated defects while the patella is stabilized using a minimally invasive percutaneous fixation technique with screws and a tension band construct.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Modified Tension Band Fixation Technique for the Management of Patellar Fractures Using Crossed Pins and a Lateral Parapatellar Approach

The use of the tension band technique for patellar fracture fixation has been associated with a loss of the rigidity of the construct after cyclic loading. Biomechanical studies have shown the biomechanical superiority of the crossed pin configuration relative to the traditional parallel one. Here, we describe a modified tension band technique that involves the use of crossed pins and a figure-of-eight passed as close to the bone as possible through a lateral parapatellar approach. The basic surgical technique and our case series are reviewed.