CT of Periarticular Adult Knee Fractures: Classification and Management Implications.

Periarticular knee fractures, which include fractures of the distal femur, tibial plateau, and patella, account for 5%-10% of musculoskeletal injuries encountered in trauma centers and emergency rooms. These injuries are frequently complex, with articular surface involvement. Surgical principles center on reconstruction of the articular surface as well as restoration of limb length, alignment, and rotation to reestablish functional knee biomechanics. Fixation principles are guided by fracture morphology, and thus, CT with multiplanar reformats and volume rendering is routinely used to help plan surgical intervention. Fractures involving the distal femur, tibial plateau, and patella have distinct management considerations. This comprehensive CT primer of periarticular knee fractures promotes succinct and clinically relevant reporting as well as optimized communication with orthopedic trauma surgeon colleagues by tying fracture type and key CT findings with surgical decision making. Fracture patterns are presented within commonly employed fracture classification systems, rooted in specific biomechanical principles. Fracture typing of distal femur fractures and patellar fractures is performed using Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification schemes. Tibial plateau fractures are graded using the Schatzker system, informed by a newer explicitly CT-based three-column concept. For each anatomic region, the fracture pattern helps determine the surgical access required, whether bone grafting is warranted, and the choice of hardware that achieves suitable functional outcomes while minimizing the risk of articular collapse and accelerated osteoarthritis. Emphasis is also placed on recognizing bony avulsive patterns that suggest ligament injury to help guide stress testing in the early acute period. ©RSNA, 2024 Supplemental material is available for this article.

[A new fluoroscopic view to evaluate the medial and lateral articular reduction quality in patella fractures during internal fixation].

Objective: To introduce a new fluoroscopic method for assessing the quality of medial and lateral joint surface reduction during internal fixation of patellar fractures and to summarize the clinical outcomes of patients treated using this method. Methods: A retrospective analysis was conducted on the clinical data of 52 patients with patellar fractures treated between January 2018 and January 2022 who met the inclusion criteria. There were 27 male and 25 female patients, aged 21-75 years, with an average age of 62 years. The types of patellar fractures included 9 transverse fractures, 37 comminuted fractures, and 6 longitudinal fractures. According to the AO/Orthopaedic Trauma Association (AO-OTA)-2018 fracture classification, there were 21 cases of type 34A, 6 cases of type 34B, and 25 cases of type 34C. The time from injury to operation ranged from 1 to 5 days, with an average of 2.3 days. Treatments included internal fixation with hollow screws or hollow screw tension bands, with or without anchor repair. During operation, the medial and lateral joint surfaces of the patella were observed using the tangential fluoroscopic method to assess the smoothness of reduction of the median ridge, lateral joint surface, medial joint surface, and lateral joint edge. Patients were followed up regularly, and X-ray films were taken to observe fracture healing. Knee joint range of motion, Böstman score, and Lysholm score were used to evaluate functional recovery. Results: The tangential fluoroscopic method for the medial and lateral joint surfaces of the patella during operation showed satisfactory reduction of the joint surfaces and good positioning of the implants. All patients were followed up 12-16 months, with an average of 13.4 months. During the follow-up, fracture displacement occurred in 1 case and titanium cable breakage in 1 case. All patella fractures healed successfully, with a healing time of 8-16 weeks (mean, 11.4 weeks). At last follow-up, knee joint range of motion ranged from 120° to 140°, with an average of 136°. The Böstman score ranged from 20 to 30, with an average of 28, yielding excellent results in 45 cases and good results in 7 cases. The Lysholm score ranged from 88 to 100, with an average of 93, yielding excellent results in 40 cases and good results in 12 cases. Conclusion: The intraoperative application of the tangential fluoroscopic method for the medial and lateral joint surfaces of the patella can quickly determine the fluoroscopic plane of the patella, accurately assess the quality of fracture reduction and the position of internal fixator, thereby improving effectiveness.

Reconstruction of patella fractures with the tension band technique: A review on clinical results and tips and tricks.

INTRODUCTION: The goals of surgical treatment of patellar fractures are a biomechanically stable joint and congruent restoration of the retro patellar joint surface. Surgical treatment strategies for patellar fractures have evolved from tension band in combination with wire cerclages to new devices. METHODS: The modified anterior tension band (MATB) technique for fixation of patellar fractures consists of two longitudinal 1.8 mm Kirschner wires (K-wires) and an 18-gauge stainless steel wire looped in a figure-of-8 pattern over the anterior aspect of the patella. The K-wires should be inserted 5 mm from the anterior cortical surface of the patella, parallel in the coronal and sagittal planes. For mechanical reasons, the wire should be the closest to the anterior aspect of the bone. This construct converts the anterior tensile forces generated by the extensor mechanism and knee flexion into compressive forces on the anterior aspect of the fracture site. The MATB is the most widely accepted method of internal fixation for transverse and comminuted patellar fractures. Only a careful implementation of the MATB in all its phases will provide the best mechanical construct and the least aggressive construct for the soft tissues, allowing early re-education without complications. RESULTS: Good to excellent clinical results (64-100 %) have been reported with MATB for fixation of patellar fractures. Good to excellent range of knee motion and satisfactory results have been reported despite a high percentage (up to 60 %) of secondary procedures, mainly for removal of symptomatic hardware. CONCLUSION: This article provides an overview of the use and results of the MATB technique for patellar fractures and the means to improve results with this technique.

An innovative anti-rotation tension band wiring for treating transverse patellar fractures: finite element analysis and mechanical testing.

BACKGROUND: The displacement and rotation of the Kirschner wire (K-wire) in the traditional tension band wiring (TBW) led to a high rate of postoperative complications. The anti-rotation tension band wiring (ARTBW) could address these issues and achieve satisfactory clinical outcomes. This study aimed to investigate the biomechanical performance of the ARTBW in treating transverse patellar fracture compared to traditional TBW using finite element analysis (FEA) and mechanical testing. METHODS: We conducted a FEA to evaluate the biomechanical performance of traditional TBW and ARTBW at knee flexion angles of 20°, 45°, and 90°. Furthermore, we compared the mechanical properties under a 45° knee flexion through static tensile tests and dynamic fatigue testing. The K-wire pull-out test was also conducted to evaluate the bonding strength between K-wires and cancellous bone of two surgical approaches. RESULTS: The outcome of FEA demonstrated the compression force on the articular surface of ARTBW was 28.11%, 27.32%, and 52.86% higher than traditional TBW at knee flexion angles of 20°, 45°, and 90°, respectively. In mechanical testing, the mechanical properties of ARTBW were similar to the traditional TBW. In the K-wire pull-out test, the pull-out strength of ARTBW was significantly greater than the traditional TBW (111.58 ± 2.38 N vs. 64.71 ± 4.22 N, P < 0.001). CONCLUSIONS: The ARTBW retained the advantages of traditional TBW, and achieved greater compression force of articular surface, and greater pull-out strength of K-wires. Moreover, ARTBW effectively avoided the rotation of the K-wires. Therefore, ARTBW demonstrates potential as a promising technique for treating patellar fractures.

[Comparison of effectiveness of tibial intramedullary nailing fixation via suprapatellar approach and medial parapatellar approach in treatment of multiple tibial fractures].

Objective: To compare the effectiveness of intramedullary nailing fixation via suprapatellar approach and medial parapatellar approach in semi-extended position in the treatment of multiple tibial fractures. Methods: The clinical data of 43 patients with multiple tibial fractures treated with intramedullary nailing fixation between July 2018 and December 2022 were retrospectively analyzed, including 23 patients treated with suprapatellar approach in semi-extended position (group A) and 20 patients with medial parapatellar approach in semi-extended position (group B). There was no significant difference in gender, age, cause of injury, time from injury to operation, AO/Orthopaedic Trauma Association (AO/OTA) classification, preoperative visual analogue scale (VAS) score, and range of motion (ROM) of the knee joint between the two groups ( P>0.05). The operation time, intraoperative blood loss, incision length, intraoperative fluoroscopy frequency, and fracture healing time were recorded and compared. The VAS score and ROM of the knee joint were analyzed at 4, 8, and 12 weeks after operation, and the incidence of postoperative complications was observed; knee function was evaluated by Lysholm score at last follow-up. Results: The operations were successfully completed in both groups, and there was no complication such as nerve and blood vessel injury during operation, and all incisions healed by first intention. There was no significant difference in operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency between the two groups ( P>0.05), but the incision length in group B was significantly longer than that in group A ( P<0.05). Patients in both groups were followed up 12-30 months, with an average of 21.1 months. The VAS score decreased and ROM increased gradually in both groups with time after operation, showing significant differences between different time points ( P<0.05). The VAS score of group B was significantly lower than that of group A at 4 and 8 weeks after operation ( P<0.05); there was no significant difference in VAS score and ROM between the two groups at other time points ( P>0.05). There was no significant difference in fracture healing time between the two groups ( P>0.05). During the follow-up, there was no complication such as internal fixator loosening, breakage, and loss of fracture reduction. At last follow-up, the Lysholm score in group B was significantly better than that in group A ( P<0.05). Conclusion: Both the suprapatellar approach and the medial parapatellar approach in semi-extended position can achieve satisfactory results in the treatment of multiple tibial fractures. The medial parapatellar approach has lower symptoms of early knee pain and better long-term function.

Patient Characteristics and Postoperative Outcomes of Surgically Treated Inferior Pole Patellar Sleeve Fractures.

BACKGROUND: Despite representing over half of all pediatric patella fractures, inferior pole patellar sleeve fractures (PSFs) are a relatively uncommon pediatric injury. As a result, existing literature on PSFs is limited to case reports and small case series. The purpose of this study was to evaluate the radiographic and clinical characteristics of operatively treated PSFs as well as outcomes following surgical management. METHODS: A retrospective review of all inferior pole PSFs requiring surgery from 2007 to 2023 was performed at a single urban tertiary care children's hospital. Cases were identified using diagnostic and billing codes. Patient demographics, injury characteristics, surgical techniques, and postoperative rehabilitation practices were recorded. Regional skeletal maturity, fracture characteristics, and postreduction patellar height were recorded. Postoperative complications were recorded and categorized using the modified Clavien-Dindo Classification System (CDS). RESULTS: Thirty-eight inferior pole PSFs were identified meeting study criteria. The majority of patients were male (86.8%), and the mean age at injury was 11.0 years (range: 7.2 to 15.0). Mean BMI was 21.1. Radiographically, the majority of patients were Epiphyseal Fusion Stage 0 (nonunion), with a median postreduction Caton-Deschamps index (CDI) of 1.2 (IQR: 1.1 to 1.3). These fractures were predominantly treated with suture-based fixation (84%). Postoperative immobilization varied within the cohort, and the initiation of knee ROM was permitted at a median of 3.5 (IQR: 2.0 to 4.6) weeks. All patients regained full range of motion and straight leg raise without extensor lag, and return-to-sport was achieved by a median of 17.6 weeks (IQR: 12.8 to 30.3). Complications occurred in 10 (26.3%) patients, with 3 (7.9%) requiring a return to the OR (CDS Grade III). CONCLUSIONS: Inferior pole PSFs appear to occur most commonly among prepubertal males of normal BMI and normal patellar height. Despite variable rehabilitation protocols, operative management resulted in restoration of extensor mechanism function. Eight percent of patients experienced complications requiring unplanned surgery. This large series improves our understanding of the epidemiology, injury characteristics, and postoperative outcomes of an operatively treated cohort of a rare injury pattern. LEVEL OF EVIDENCE: Level IV.

Articular Fragment Detachment and Separate Fixation for the Treatment of Comminuted Patellar Fractures with Coronal Split Articular Fragments: Articular Detachment Technique.

Background: Treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments is a challenge. To treat this difficult fracture, we perform articular fragment detachment and separate fixation for coronal split articular and inferior pole fragments. We aimed to evaluate the radiological and clinical outcomes of our technique in comminuted patellar fractures at least 1 year after surgery. Methods: Between January 2019 and June 2022, 15 patients diagnosed with comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments based on preoperative computed tomography underwent surgery using the articular detachment technique. The key point of this technique was anatomical reduction and subchondral fixation of the coronal split articular fragment to the superior main fragment after complete detachment of the coronal split fragment from the inferior pole. The remaining inferior pole was fixed using a separate construct. Postoperative articular gap, articular step-off, and complications, including resorption, reduction loss, and avascular necrosis of fixed articular fragments, were evaluated as radiological outcomes. Range of motion and the Lysholm scores were used to evaluate clinical outcomes. Results: Among the 15 patients, the coronal split articular fragments were fixed using Kirschner wires in 13 patients and headless screws in 2 patients. The inferior poles were fixed using separate vertical wiring in 13 patients and tension-band wiring in 2 patients. A postoperative articular gap was noted in 7 patients, with an average articular gap of 1.0 mm (range, 0.7-1.6 mm). No articular step-off was observed. Bone union and normal range of motion were achieved in all patients. On the 1-year postoperative lateral radiograph, resorption of the articular fracture site was seen in 5 patients. There was no loss of reduction or avascular necrosis of the coronal split articular fragments. The average postoperative Lysholm score at 1 year was 89.3 ± 4.1 (range, 82-95). Conclusions: The technique would be a reliable and safe option for the surgical treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments in terms of anatomical reduction and stable fixation of articular fragments without risk of avascular necrosis.

Tension band versus locking plate fixation for patella fractures - a protocol of a randomised controlled trial.

INTRODUCTION: Following surgical management of patella fractures, patients commonly report pain; difficulties with weight-bearing tasks such as walking, running and climbing stairs; and restrictions in quality of life. Recently, a locking plate system for surgical management of patella fractures has been introduced. To date, no studies have compared standard treatment with tension band wiring with locking plate fixation in a randomised study design. We aim to compare the one-year patient-reported Knee Injury and Osteoarthritis Outcome subscale scores (KOOS5-subscales) after standard care tension band fixation with locking plate fixation for patients with patella fractures. METHODS: This is a multicentre randomised and prospective clinical trial. A total of 122 patients will be included in the study, and the primary outcome will be the KOOS subscales at 12 months after surgery. CONCLUSIONS: Findings from the present study are expected to advance our understanding of outcome following surgical treatment of patella fractures. FUNDING: This study is funded, in part, by the Novo Nordisk Foundation, Denmark. CLINICALTRIALS: gov ID: NCT04891549.

Serial Change in Patellar Height after Tension Band Wiring of Patellar Fractures.

Background and Objectives: Patella baja is a common complication after operative treatment for patellar fracture. This study aimed to investigate (1) the serial changes in patellar height and (2) the potential predictive factors for patellar height changes after tension band wiring (TBW) for patellar fractures. Materials and Methods: Forty-one patients who underwent TBW for patellar fracture between March 2019 and September 2022 were enrolled. To identify serial changes in patellar height, modified Blackburne-Peel index (mBPI) was assessed at just after surgery, at 3 months, at 6 months, at 1 year and at the final follow-up. Multiple regression analysis was conducted to identify factors correlated with mBPI difference between the contralateral side (considered as preoperative status) and injured side. Results: The postoperative mBPI exhibited a decline over time (mean mBPI immediately post operation/3 months/6 months/1 year/final follow-up: 0.69/0.63/0.63/0.62/0.61) Specifically, mBPI showed a significant reduction immediately post operation to 3 months (p < 0.001), although comparisons at other time points did not reveal significant differences. A lower position of the fracture was associated with a decrease in patellar height after surgery. Conclusions: Patellar height was mainly decreased from immediately post operation to 3 months. A fracture in a lower position of associated with decreased patellar height after the TBW of the transverse patellar fracture.

Management of complete intra-articular distal femur and patellar fractures in an achondroplastic young adult; small is challenging' revisited: a case-report.

BACKGROUND: People with achondroplasia exhibit distinct physical characteristics, but their cognitive abilities remain within the normal range. The challenges encountered during surgical procedures and perioperative care for achondroplastic individuals, are underrepresented in the existing literature. CASE PRESENTATION: In this report, the management of a 26-year-old North-African achondroplastic male is highlighted. The patient suffered a complete intra-articular distal femur fracture (AO/OTA 33-C1) and an ipsilateral patella fracture (AO/OTA 34-C1). The patient's unusual anatomical variations and the lack of suitable orthopedic implants posed significant surgical challenges, particularly in the context of a resource-limited developing country. Facial and spinal deformities, which are common in patients with achondroplasia, further complicated the anesthetic approach. CONCLUSIONS: The limited information on operative management of fractures in achondroplastic patients necessitated independent decision-making and diverging from the convenient approach where clear guidance is available in the literature.

Study on the therapeutic effect of Kirschner wire tension band combined with anchor cross-stitch technique in the treatment of comminuted patellar inferopolar fractures.

PURPOSES: Fractures of the inferior patellar pole, unlike other patellar fractures, present challenges for traditional surgical fixation methods. This article introduces the clinical technique and outcomes of using Kirschner wire tension band combined with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures. METHODS: This retrospective case series study included 14 patients with comminuted inferior patellar pole fractures treated at our institution from September 1, 2020, to April 30, 2022. All patients underwent surgery using the Kirschner wire tension band with anchor screw cross-stitch technique. Follow-up assessments involved postoperative X-rays to evaluate fracture healing, as well as clinical parameters such as healing time, Visual Analog Scale (VAS) scores, range of motion (ROM), and Bostman scores. RESULTS: All patients were followed for an average of over 12 months, with no cases of internal fixation failure. Knee joint stability and function were excellent. X-rays revealed an average healing time of approximately 10.79 ± 1.53 weeks, hospitalization lasted 5.64 ± 1.15 days, surgery took approximately 37.86 ± 5.32 minutes, and intraoperative blood loss was 33.29 ± 8.15 ml. One patient experienced irritation from the internal fixation material. At the final follow-up, the Bostman score averaged 28.29 ± 0.83, knee joint flexion reached 131.07° ± 4.88°, all patients achieved full knee extension, and the VAS score was 0.36 ± 0.63. CONCLUSION: Kirschner wire tension band with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures delivered satisfactory clinical outcomes. This surgical method, characterized by its simplicity and reliability, is a valuable addition to clinical practice.

A retrospective investigation on clinical and radiographic outcomes of distal tibial fractures after intramedullary nailing using the lateral parapatellar extra-articular approach.

INTRODUCTION: According to reports, the modified extra-articular parapatellar approach allows the performance of tibial nailing in the semi-extended position without the concern of joint violation. However, there remains no special study that has provided a detailed assessment of the benefits and risks of this approach for treating distal tibial fractures (DTFs). The aim of this retrospective study was to investigate the clinical and radiological outcomes of patients with DTFs after intramedullary nailing using a lateral parapatellar extra-articular (LPE) approach in comparison to using the suprapatellar (SP) and transpatellar (TP) approaches. METHODS: Data were collected from 99 patients with a minimum follow-up period of 12 months. Comparisons were conducted between the groups regarding the number of intraoperative fluoroscopies, complications, knee pain, knee range of motion (ROM), the Lysholm Knee Scale (LKS), the Olerud-Molander Ankle Score (OMAS) and radiological findings. RESULTS: The demographic characteristics were comparable between the groups. Fewer intraoperative fluoroscopies were performed in the LPE (27.47 ± 4.98) and SP (26.03 ± 5.12) groups than in the TP group (30.20 ± 7.42; P<0.001). When compared with the other two approaches, the LPE approach was associated with less knee pain (P<0.001) and better knee ROM (P<0.001) at one week postoperative. No significant intergroup differences were detected in the incidence of complications, LKS scores (P = 0.687) and OMAS (P = 0.926). Radiological findings demonstrated that postoperative tibial alignment (P = 0.853), the time of bony union and rate of non-union were similar between the groups. CONCLUSION: The LPE approach can serve as a safe and effective option for tibial nailing, as it offers favourable outcomes in knee pain relief and knee ROM in the early postoperative period and is equivalent to the other two approaches in terms of the incidence of complications, fracture healing, functional recovery and postoperative alignment for patients with DTFs.

Distinct risk profiles for short-term surgical complications and venous thromboembolism exist among extensor mechanism repair procedures.

PURPOSE: Extensor mechanism injuries, which comprise patella fractures, patella tendon tears and quadriceps tendon tears, are severely debilitating injuries and a common cause of traumatic knee pathology that requires surgical intervention. Risk factors for short-term surgical complications and venous thromboembolism (VTE) in this population have not been well characterised. The aim of this study was to identify perioperative risk factors associated with these short-term complications. METHODS: The National Surgical Quality Improvement Program database was used to identify patients who underwent an isolated, primary extensor mechanism repair from 2015 to 2020. Patients were stratified by injury type. Demographic data were collected and compared. A multivariate logistic regression was used to control for demographic and comorbid factors while assessing risk factors for developing short-term complications. RESULTS: A total of 8355 patients were identified for inclusion in this study. Overall, 3% of patients sustained short-term surgical complications and 1% were diagnosed with VTE within 30 days of surgery. Patella fracture fixation had a nearly twofold higher risk for surgical complications compared to quadriceps tendon repair (p = 0.004). Patella tendon repair had a twofold higher risk for VTE (p = 0.045), specifically deep vein thrombosis (p = 0.020), compared to patella fracture fixation. Increasing age, smoking and American Society of Anesthesiologists Classifications 3 and 4 were also found to be risk factors for surgical complications (p = 0.012, p = 0.004, p = 0.011 and p = 0.032, respectively). CONCLUSION: This study used a nationally representative, widely validated, peer-reviewed database to provide valuable insights into risk factors for short-term postoperative complications associated with extensor mechanism repair procedures, revealing notable differences in risk profiles among distinct surgical procedures. The results of this study will inform surgeons and patients in enhancing risk assessment, guiding procedure-specific decision-making, optimising preoperative care, improving postoperative monitoring and contributing to future research of extensor mechanism injuries. LEVEL OF EVIDENCE: Level III.

Effect of Patellar Morphology on the Risk of Osteochondral Fracture after Patellar Dislocation: A Cross-sectional Study.

OBJECTIVE: The risk of osteochondral fracture (OCF) after patellar dislocation has been shown to be related to patellofemoral anatomy, but its relationship to patellar morphology remains unknown. The aim of this study was to investigate the associations between patellar morphology and the risk of OCF after patellar dislocation. METHODS: A total of 140 patients with patellar dislocation between January 2018 and June 2023 were enrolled in this study and divided into two groups. Sixty-five patellar dislocation patients with OCF were included in the OCF group, while 75 patellar dislocation patients without OCF were included in the non-OCF group. Computed tomography was used to compare measurements of patellar morphology including Wiberg classification, patellar width and thickness, Wiberg angle, Wiberg index, facet ratio, lateral patellar facet angle, and patellar tilt angle. A logistic regression model was performed to evaluate the correlations between patellar morphology and the risk of OCF after patellar dislocation. Receiver operating characteristic curves were used to calculate the area under the curve (AUC) and determine the diagnostic values of patellar morphology for OCF after patellar dislocation. Subgroup analyses for gender and age were conducted to compare the differences in patellar morphology of PD patients. RESULTS: Wiberg angle was significantly lower in the OCF group (p = 0.017), while Wiberg index (p = 0.002) and facet ratio (p = 0.023) were significantly higher in the OCF group. According to the results of logistic regression analysis, Wiberg angle (odds ratio [OR] = 0.96, p = 0.022) and Wiberg index (OR = 1.105, p = 0.032) were the final relevant factors for the occurrence of OCF after patellar dislocation. The AUC was 0.622 (95% confidence interval [CI]: 0.529-0.714) for Wiberg angle, 0.65 (95% CI: 0.558-0.742) for Wiberg index, and 0.702 (95% CI: 0.615-0.788) for the combination of Wiberg angle plus Wiberg index. CONCLUSION: Wiberg angle and Wiberg index were independent risk factors for the occurrence of osteochondral fracture after patellar dislocation. Moreover, Wiberg angle, Wiberg index, and the combination of Wiberg angle plus Wiberg index had good predictive diagnostic value for the occurrence of OCF after patellar dislocation.

Patellar Fracture Surgery Performed Autonomously by Residents, Yields Similar Short-Term Outcomes to Surgery Performed by Fellowship-Trained Surgeons.

BACKGROUND: Open reduction and internal fixation are the gold-standard treatment for displaced patellar fractures. The current literature remains inconclusive on the relationship between resident participation in the operating room and optimal patient outcomes. We hypothesize that surgeries performed solely by residents, without attending supervision, can provide similar outcomes to those performed by fellowship-trained orthopedic surgeons, providing new insights into the relationship between resident autonomy and surgical outcomes in the field of orthopedic trauma. METHODS: A tertiary trauma center cohort was retrospectively reviewed for all surgically treated patellar fractures between 2015 and 2020. The cohort was divided into 2 groups: patients operated by residents and patients operated by orthopedic trauma specialists. Demographics, surgical parameters, and radiographs were compared between the groups to evaluate complications and reoperation rates, radiographic outcomes (such as hardware failure, or loss of reduction), and clinical outcomes (including residual pain, painful hardware, decreased range of motion, and infections). RESULTS: A total of 129 patellar fractures were included in the study. Demographics and ASA were similar between the groups. There were no significant differences in complications (p = 0.900) or reoperation rates (p = 0.817), with an average follow-up time of 8 months (SD ± 5.3). Residents had significantly longer surgery duration (p =0.002). However, the overall length of stay was shorter in the resident group (p < 0.001). CONCLUSION: The study shows patellar fracture surgery performed by adequately trained residents can provide similar outcomes to those performed by fellowship-trained orthopaedic trauma surgeons. These findings highlight the significance of surgical autonomy in residency and its role in contemporary surgical education.

Transverse patella fracture fixation: A cadaveric biomechanical comparison of cannulated screws and anterior tension band versus low-profile, multiplanar mesh plating.

INTRODUCTION: Multiplanar mesh plating of patella fractures has become more popular in recent years. It was the goal of this study to compare the biomechanical stability of cannulated screw with anterior tension band to multiplanar mesh plating for fixation of transverse patella fractures in cadaver specimens. MATERIALS AND METHODS: Eight matched pairs of fresh frozen cadaveric knees were obtained and soft tissues dissected leaving the extensor mechanism, joint capsule, and retinaculum intact. Transverse fractures were created at the mid-portion of the patella. For each pair, one specimen was repaired using cannulated screws with anterior tension band, and the second was repaired using multiplanar mesh plating. Each specimen underwent cyclic extension loading with loads increasing by 1.1 kg after every 50 cycles. Interfragmentary displacement was measured at the end of each interval at both 5° and 45° of knee flexion angle, with fixation failure defined by >2 mm displacement. RESULTS: The specimens fixed with multiplanar mesh plating survived more cycles and higher loads than the specimens fixed with cannulated screws with anterior tension band (p = 0.011 comparing survival plots). After 150 cycles of extension loading, 3 of 8 of the specimens fixed with screws/tension band had failed, whereas none of the mesh plated specimens had failed. After 400 cycles, 7 of 8 of the screws/tension band had failed, whereas half of the mesh plated specimens had failed. CONCLUSIONS: While a more technically challenging and expensive technique, mesh plating for patella fractures appears to offer greater durability than traditional cannulated screw with tension banding.

Reconstruction of the extensor mechanism using polypropylene mesh in a displaced pathological fracture of the patella affected by giant cell tumour.

A man in his 30s came to our clinic with a year-long history of progressive pain and swelling in his knee. Diagnostic imaging revealed a displaced patellar fracture with an osteolytic, septated lesion and thinned expanded cortex in both fracture fragments. A core needle biopsy confirmed the diagnosis of giant cell tumour. Treatment involved wide excision of the tumour and the use of polypropylene mesh and a peroneal longus tendon autograft to reconstruct the extensor mechanism of the knee joint. One year postoperatively, the patient experienced no pain, demonstrated full range of motion and showed no signs of functional impairment or local tumour recurrence. This case highlights that reconstruction of the extensor mechanism of the knee after tumour excision with synthetic mesh is an affordable, user-friendly and widely accessible method. It can address large defects effectively while minimising the risks of disease transmission and graft lengthening, resulting in satisfactory outcomes.

Lateral rim variable angle locked plating versus tension band wiring of simple and complex patella fractures: a biomechanical study.

INTRODUCTION: Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. MATERIALS AND METHODS: Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. RESULTS: For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.