Surgery of patellar fractures using a medial parapatellar approach

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.

Anterior variable-angle locked plating versus tension band wiring of simple and complex patella fractures - a biomechanical investigation

BACKGROUND

The aim of this study was to investigate the biomechanical performance of novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures.

METHODS

Sixteen pairs of human cadaveric knees were used to simulate two-part simple transverse AO/OTA 34-C1 and five-part complex AO/OTA 34-C3 patella fractures. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patella pole. Eight pairs with simple fractures were split for fixation via either tension band wiring (TBW) through two parallel cannulated screws or anterior variable-angle locked plating, whereas other eight pairs with complex fractures were split for either TBW through two parallel cannulated screws plus circumferential cerclage wiring, or anterior variable-angle locked plating using a cortical caudo-cranial polar screw. Each specimen was tested over 5000 cycles with a range of motion from 90° flexion to full extension by pulling on the quadriceps tendon. Interfragmentary movements were captured by motion tracking.

RESULTS

For both fracture types, the longitudinal and shear 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 anterior variable-angle locked plating versus TBW, p ≤ 0.01.

CONCLUSIONS

From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures resulted in less interfragmentary displacement under extended cyclic loading.

Immunohistochemical analysis of the quadriceps femoris muscle before and after total knee arthroplasty

BACKGROUND

The number of total knee arthroplasties (TKA) has increased steadily with the aging of the population. This surgical procedure is recognized for its success in pain relief and restoration of knee function. However, decreased quadriceps femoris (QF) muscle strength after TKA is frequently observed but with unknown etiology. Evidence suggests that the location of the operative incision (i.e., surgical access) can influence QF muscle structure and function. The present study aimed to assess the fiber type composition, structure and assembly of the QF's vastus medialis (VM) and vastus lateralis (VL) muscles before and after TKA.

METHODS

Muscle biopsies (VM and VL muscles) were collected from patients previously submitted to TKA via the medial parapatellar route and undergoing TKA revision (main group, n = 9) and patients with osteoarthrosis (OA) who were due to undergo TKA (control group: n = 18). The biopsied muscle tissue was prepared, stored, and then sectioned in a cryostat at -25 °C. The tissue sections were evaluated using routine staining techniques in pathological anatomy and histochemistry.

RESULTS

The normal mosaic pattern of the medial and lateral knee muscles was observed in the main and control groups, with no evidence of peripheral nerve damage. Notably, 88.9 % of the patients exhibited mild to severe VL atrophy, while only 11.1 % of patients in the control group presented this feature (P < 0.001).

CONCLUSIONS

The medial parapatellar incision for TKA surgical access does not generate definitive morphological changes in the VM and VL muscle fibers but may contribute to VL atrophy.

A minimally invasive bipolar surgical approach for the treatment of patellar fracture using the tension-band wiring technique

Objective

Minimally invasive surgical techniques are becoming increasingly popular for the treatment of traumatic injuries. Although some minimally invasive techniques in the management of patellar fractures have been reported, the limited exposure in such methods may cause technical difficulties during surgery and restrict their wide application. In this context, this study aims to introduce a bipolar incision and assess the clinical outcomes of patellar fractures treated via this type of incision.

Materials and methods

Patients who suffered patellar fractures and who received surgical treatment via bipolar incision between 2018 and 2020 in our hospital were retrospectively reviewed and included in this study. The clinical and radiological records of all patients were reviewed. A classification of the fractures was done and intraoperative parameters, Visual Analog Scale (VAS) score, knee range of motion, and the Hospital for Special Surgery (HSS) knee score of the patients were evaluated and summarized.

Results

The study included 19 patients who met the inclusion criteria. All patellar fractures were operated through the minimally invasive bipolar surgical approach. The mean time of operation was 69.0 ± 8.5 min. The mean time to union was 12.8 ± 2.1 weeks. The average total knee range of motion was 131.8 ± 4.4°, and the average HSS score was 97.1 ± 2.6 at 1-year post-operation. No surgical-related complications were observed.

Conclusions

The knee functional outcomes were favorable when patellar fractures were treated through the minimally invasive bipolar incision method. This bipolar surgical approach was found to be a feasible method for treating patellar fractures.

Surgical Management with Self-Locking Pins and Circumferential Wiring for Treating Comminuted Patella Fractures Achieved Seiza-Style Sitting

Surgical fixation of comminuted patella fractures is technically challenging. Despite the fact that tension band wiring or screw fixation are the most common surgical procedures, these surgical techniques have crucial limitations for laterally scattered fragments. We demonstrate two cases with comminuted patella fractures undergoing surgical fixation with self-locking pin and circumferential wiring, confirming the rigid fixation achieving deep knee flexion. After midline longitudinal skin incision, 2.0 mm stainless pins (AiMedic MMT, Tokyo, Japan) were inserted radially to penetrate each fragment and 1.2 mm stainless wire was circumferentially looped and self-locked in the holes on the pins, which satisfied rigid fixation. Any restrictions in range of motion and weight bearing were required postoperatively and 3- to 6-month postoperative cares achieved seiza-style sitting with deep knee flexion.

Patella Fractures: Approach to Treatment

Patellar fracture morphology varies based on the mechanism of injury. Most fractures are either a result of direct impact or through an indirect eccentric extensor contraction injury. Each fracture pattern requires appropriate preoperative planning and individualization of the fixation method. Displaced fractures affect the extension apparatus, and often require surgical fixation. Surgical treatment is recommended in fractures with any of the following features: articular step-off > 2 mm, > 3 mm of fracture displacement, open fractures, and displaced fractures affecting the extensor mechanism. Meticulous handling of the soft-tissue envelope is of the utmost importance, given the patella's tenuous blood supply and limited soft-tissue envelope. Incongruent articular surface can result in detrimental long-term effects; therefore, surgical treatment is directed toward anatomic reduction and fixation. The evolution of patellar fracture fixation continues to maximize options to balance rigid fixation with low-profile fixation constructs. Improving functional outcomes, minimizing soft-tissue irritation, and limiting postoperative complications are possible by using the therapeutic principles of rigid anatomical fixation and meticulous soft-tissue handling.

Miniplate osteosynthesis in fracture surgeries: Case series with review of concepts

PURPOSE

Miniplates were initially developed as targets for foot and hand fractures, but they have been used in the treatment of fixation of small bone fragments, reduction of long bone fractures and non-union treatment, which have been difficult to treat. In this study, the authors used miniplates to treat fractures of the upper extremities, lower extremities, and pelvis obtained good outcomes. Herein, the authors report these good outcomes and review the current concept of miniplates.

PATIENTS AND METHODS

Forty-two patients treated with miniplates between March 2012 and March 2017 who attended follow-up for > 1 year were included in this retrospective study. Miniplates were selected according to purpose, which was classified into three categories: fixation, reduction, and stability enhancement. For fixation, miniplates were used to fix distal fibular fractures occurring distal to the syndesmosis and treat patellar and olecranon fractures with severe comminution. For reduction, miniplates were used to reduce the tibia during intramedullary nailing in tibiofibular shaft fractures, while reduction was performed in advance of definitive plating fixation in patients with humeral and pelvic fractures. To enhance stability, the miniplate was inserted after autobone graft for atrophic nonunion at the humeral shaft following nail insertion. The validity of a miniplate was analyzed by reviewing the published literature on the use of miniplates in orthopedic fracture surgeries.

RESULTS

Bony union was achieved in all cases. No specific postoperative complications were observed; however, mild pain and limited range of motion observed in two patients were resolved after implant removal. Sixteen studies on fracture treatment using miniplates reported clinically fair outcomes.

CONCLUSION

Miniplates are not just small metal plates. Depending on the location and treatment of the fracture, the miniplate can effectively fix small bone fragments, help the main plate to maintain the reduction of large bone fragments, and increase the fixation force for nonunion treatment.

Clinical observation of C3-type patellar fractures treated by operation methods with or without a turned-over patella

OBJECTIVE

To evaluate the clinical efficacy of operation methods with or without a turned-over patella for treatment of C3-type patellar fractures.

METHODS

A total of 68 patients with C3-type patellar fractures undergoing open reduction and internal fixation were retrospectively selected and treated with a turned-over patella surgery (turned-over patella group, n = 30) or conventional therapy without turning over the patella (conventional group, n = 38). The intraoperative and postoperative indicators of the two groups were assessed and comparatively analyzed.

RESULTS

The bedridden time was significantly shorter in the turned-over patella group than in the conventional group (P = 0.002), while the range of motion (ROM) of knee joint was significantly higher in the turned-over patella group (P = 0.044). The Lysholm score was slightly higher in the turned-over patella group than in the conventional group, but the difference was not statistically significant (P = 0.055). No significant difference was observed between the two groups in terms of the operation time (P = 0.096), intraoperative blood loss (P = 0.543), time of weight bearing (P = 0.312), fracture healing time (P = 0.272), or complications (P = 1).

CONCLUSION

The turned-over patella operation method exhibited some superiority to conventional reduction-fixation approach for treatment of C3-type patellar fractures in terms of efficacy and safety by enlarging the ROM of the knee joint and promoting functional recovery.