Hoffa fractures are associated with concomitant soft tissue injures and a high postoperative complication rate

INTRODUCTION

Hoffa fractures are a rare and often overlooked entity. The main goal of surgical treatment is to restore the articular surface and maintain knee function. However, current clinical data indicate heterogeneous outcomes. The aim of this multicenter study was to obtain a representative data set of patients with isolated Hoffa fractures with special emphasis on concomitant soft tissue injuries, diagnostic algorithms, treatment strategies and functional outcomes.

MATERIALS AND METHODS

Participating Level I trauma centres were asked to review their internal database for isolated Hoffa fractures treated surgically between 2010 and 2020. Demographics, mechanism of injury, diagnostic and therapeutic algorithm, Letenneur classification, concomitant soft tissue injuries, and postoperative knee function and complications were analysed.

RESULTS

A total of 56 patients from six participating trauma centres were included. The median age at injury was 45 years (15-94) with a median follow-up of 19 months (2-108). The most common mechanism of injury was high-energy trauma, with unicondylar lateral Letenneur type I and II fractures being the most common. Surgical treatment was independent of the type of fracture and included isolated screw fixation, combined plate and screw fixation and isolated plate osteosynthesis. Isolated screw fixation resulted in significantly better range of motion (ROM) values (p = 0.032), but the highest number of postoperative complications (n = 14/20, n.s.) compared to the other fixation techniques. The highest number of fixation failures requiring revision was observed in the plate and screw fixation group (n = 3/8, p = 0.008). Osteochondral flake fractures (n = 12/43, 27%) and lateral meniscus injuries (n = 5/49, 10%) were commonly seen in Hoffa fractures.

CONCLUSIONS

Treatment of Hoffa fractures with screw fixation resulted in significantly better functional outcomes, probably due to less comminuted fractures. Concomitant cartilage, meniscal and ligamentous injuries are common and warrant preoperative recognition and management.

Missed Medial Condyle Hoffa Fracture in a Case of Lateral Condyle Hoffa Fracture

Introduction

The Hoffa fracture is an uncommon coronal plane fracture involving the femoral condyles. The coronal nature of the fracture makes it hard to diagnose clinic-radiologically.

Case Report

A 42-year-old male patient developed pain associated with swelling in his right knee after a two-wheeler accident. He consulted his general practitioner who missed the Hoffa fracture on plain radiographs and treated him conservatively with analgesics. The pain did not subside and he visited our emergency department where a computed tomography (CT) scan revealed a Hoffa fracture of the lateral condyle. He was taken up for open surgery, and while fixing the lateral condylar fracture, we found an undisplaced medial condylar Hoffa fracture of the ipsilateral femur. This fracture was initially missed on the CT scan. Both the fractures were internally fixed and the patient was put on rehabilitation. At the end of the 6-month follow-up, the patient had a full knee range of motion.

Conclusion

Careful and detailed CT imaging and looking for fractures other than Hoffa is important, so as not to miss any associated bony injuries. Furthermore, the treating surgeon needs to look for other bony injuries during open or arthroscopic fixation of Hoffa's fracture.

Non-union lateral femoral condyle Hoffa fracture: a case report

An isolated Hoffa fracture of either of the femoral condyle is infrequently encountered. Owing to its rarity, it is often missed and subsequently results in non-union. The knowledge of its surgical management comes from the sporadically reported cases in the literature. The most preferred approach is parapatellar, providing adequate exposure of the fracture and the joint surface. We report a case of non-union of Letteneur-2C lateral condyle Hoffa fracture of the left distal femur in a young adult as a result of missed bony injury. Surgical fixation was done using a posterolateral approach to the knee and fixing the fracture with headless compression screws placed posteroanteriorly. After about 1 year of follow up, patient demonstrated excellent functional outcome in the form of a pain free mobilisation and near normal range of motion. We emphasise the fact that the importance of vigilance while diagnosing fractures of distal femur cannot be stressed enough and with proper surgical management and rehabilitation, desirable results can be achieved.

Association of infra-patellar fat pad size with age and body weight in children and adolescents

BACKGROUND

The infra-patellar fat pad (IPFP) represents a potential mediator between obesity, low grade inflammation, and knee osteoarthritis via endocrine pathways. Yet, not only in adults, but also in childhood obesity negatively impacts knee structures.

OBJECTIVE

The current study therefore investigated the sex-specific growth of the IPFP with age and body weight in healthy children and adolescents.

MATERIALS AND METHODS

Thirty young healthy subjects (60% girls; age 4-17 years, body weight 14-90 kg in girls and 29-105 kg in boys; BMI 12.2-32.4 kg/m²) without magnetic resonance imaging (MRI) knee pathology were studied. The IPFP volume was determined from sagittal T-1 weighted and proton-density spectral attenuated inversion recovery MRIs. The primary analysis focused on the sex-specific IPFP volume/body weight ratio as dependent, and age as independent variable, using linear regression models. A secondary analytic focus was the slope of the age-dependence of IPFP volume, without normalization to body weight.

RESULTS

There was no statistically significant association of the IPFP volume/body weight ratio with age in girls (p = 0.57) or boys (p = 0.31), the R² of ranging from -0.32 to 0.14. The ratio was greater in boys (0.54 ± 0.10 cm³/kg) than in girls (0.45 ± 0.07 cm³/kg) (p < 0.01). The IPFP volume increased by approx. 2 cm³ per annum in both girls and boys, without any indication of a non-linear relationship.

CONCLUSION

Our findings reveal that the ratio of the IPFP volume and body weight remains constant between age 4 and 17 in both normal weight girls and boys, and that the IPFP volume increases linearly with age throughout this period.

Implant-associated Hoffa's Fracture in a Floating Knee: A Case Report and Review of Literature

Introduction:

Complex floating knee in the presence of a previous implant creates an unusual fracture pattern which is a rare entity and poses a unique challenge in management and subsequent rehabilitation.

Case Report:

A 56-year-old psychiatric patient who jumped from height had a polytrauma and a floating knee injury. Following the primary care and damage control surgery with knee-spanning fixator at some other centers, he was shifted to us on ventilator care and was directly admitted to intensive care unit for further management. On presentation, it was a floating knee injury with gross comminution of both femur and tibia with associated Hoffa with bent implant in situ. It was managed by plating of both lower end femur and tibia and at the end of 6 months, showed a satisfactory outcome.

Conclusion:

Floating knee injuries further complicated by the presence of the previous implant in a polytrauma situation poses a unique challenge which requires meticulous surgical planning and prolonged rehabilitation to achieve satisfactory outcome.

The infrapatellar fat pad is a dynamic and mobile structure, which deforms during knee motion, and has proximal extensions which wrap around the patella

PURPOSE

The infrapatellar fat pad (IFP) is a common cause of knee pain and loss of knee flexion and extension. However, its anatomy and behavior are not consistently defined.

METHODS

Thirty-six unpaired fresh frozen knees (median age 34 years, range 21-68) were dissected, and IFP attachments and volume measured. The rectus femoris was elevated, suprapatellar pouch opened and videos recorded looking inferiorly along the femoral shaft at the IFP as the knee was flexed. The patellar retinacula were incised and the patella reflected distally. The attachment of the ligamentum mucosum (LMuc) to the intercondylar notch was released from the anterior cruciate ligament (ACL), both menisci and to the tibia via meniscotibial ligaments. IFP strands projecting along both sides of the patella were elevated and the IFP dissected from the inferior patellar pole. Magnetic resonance imaging (MRI) of one knee at ten flexion angles was performed and the IFP, patella, tibia and femur segmented.

RESULTS

In all specimens the IFP attached to the inferior patellar pole, femoral intercondylar notch (via the LMuc), proximal patellar tendon, intermeniscal ligament, both menisci and the anterior tibia via the meniscotibial ligaments. In 30 specimens the IFP attached to the anterior ACL fibers via the LMuc, and in 29 specimens it attached directly to the central anterior tibia. Proximal IFP extensions were identified alongside the patella in all specimens and visible on MRI [medially (100% of specimens), mean length 56.2 ± 8.9 mm, laterally (83%), mean length 23.9 ± 6.2 mm]. Mean IFP volume was 29.2 ± 6.1 ml. The LMuc, attached near the base of the middle IFP lobe, acting as a 'tether' drawing it superiorly during knee extension. The medial lobe consistently had a pedicle superomedially, positioned between the patella and medial trochlea. MRI scans demonstrated how the space between the anterior tibia and patellar tendon ('the anterior interval') narrowed during knee flexion, displacing the IFP superiorly and posteriorly as it conformed to the trochlear and intercondylar notch surfaces.

CONCLUSION

Proximal IFP extensions are a novel description. The IFP is a dynamic structure, displacing significantly during knee motion, which is, therefore, vulnerable to interference from trauma or repetitive overload. Given that this trauma is often surgical, it may be appropriate that surgeons learn to minimize injury to the fat pad at surgery.

The Hoffa fracture: Coronal fracture of the femoral condyle a review of literature

This article aims to provide a systematic review of the limited literature and clinical knowledgebase available on the Hoffa fractures. It is inclusive of the normal anatomy, pathology, diagnosis, treatment options comprising of non-operative and operative protocols, and postoperative findings.

A rare case of Hoffa fracture combined with lateral patellar dislocation

The coronal unicondylar fracture of the distal femur (AO 33-B3) is a rare intraarticular injury within the weight bearing area of the knee, initially described by Albert Hoffa in 1904. We report an unusual combination of a Hoffa fracture with lateral patellar dislocation in a young adult. Our patient sustained the injury by a sudden twist of his leg during sports. He presented clinically with knee swelling, dislocation of the patella, and localized tenderness; unable to bare weight. After plane radiograph confirmed the injury, manual reduction of the patella was done by hyperextension of the knee and medialward pressure. Afterwards, a CT scan and MRI were conducted. The injury was surgically treated with lag-screws, locking-plate and MPFL-reconstruction.

Hoffa Fragments in the Geriatric Distal Femur Fracture: Myth or Reality?

Background:

Previous research reported the frequency of coronal plane (Hoffa) fractures in high-energy supracondylar femur fractures in a relatively young population. It is the purpose of this study to identify the frequency of coronal plane fractures seen in elderly patients.

Methods:

All patients over the age of 18 years treated for supracondylar femur fractures at 2 level I trauma centers were reviewed over a 4-year period. The patients were stratified (≥60 years and <60 years) and compared to determine differences in injury characteristics and fracture patterns with special attention to the prevalence of coronal plane fractures.

Results:

One hundred ten patients were identified with supracondylar femur fractures (12 Orthopaedic Trauma Association [OTA] 33A; 2 OTA 33B; 96 OTA 33C). Thirty-two of the 96 intercondylar fractures were in patients >60 years of age. The elderly group included a higher percentage of females (81% vs 36%, P = .0001) and was more likely to sustain their injury due to a fall (59% vs 19%, P = .0001). Coronal plane fractures were visualized on computed tomography scans in 56 (58%) of the 96 33C femur fractures. Forty-four percent of elderly patients sustained a coronal plane fracture compared with 66% of the younger cohort (P = .04). The percentage of open fractures (30% elderly vs 46%) was not significantly different between the 2 groups (P = .17).

Conclusions:

The occurrence rate of 44% in this study was higher than expected and is the first to provide this information in the elderly patients on this fracture. It is important that a high index of suspicion be maintained for the Hoffa fracture in all distal femur fractures, regardless of age or mechanism of injury.

Biographical background and origin of common eponymous terms in orthopedic surgery: anatomy and fractures in knee surgery

An eponym is a person after whom an eponymous term is named. These eponymous terms are easy shorthand in communication between surgeons. Therefore, they are often used and hard to eradicate. We discuss eponymous terms that describe anatomical features and fracture types in the knee. With these terms, an overview of the historical background of the eponym and its current clinical implication is discussed. The eponymous terms discussed are Gerdy tubercle, Pellegrini-Stieda lesion, Segond fracture, Hoffa fracture and fat pad. The meaning of the eponymous term is clarified, the biography of the namegiver given and its contemporary clinical implication discussed. Since eponymous terms are used frequently in inter-collegial discussion and literature, the meaning should be clear for everyone, since otherwise it might give room for misunderstanding.

Surgical management of complex intra-articular distal femoral and bicondylar Hoffa fracture

Bicondylar Hoffa's fractures of distal femur are rare. We report the case of an 18-year-old male who sustained a closed complex fracture of both femoral condyles of the left femur on the sagittal plane (Hoffa fracture), combined with distal metaphyseal fracture. He was treated using parallel plates and interdigitating screws, with our technique based on an extrapolation of the principles of distal humerus fixation. The fracture united clinically and radiologically at 16 weeks. Twelve months postoperatively, the range of movement in the knee was 5°-115°. In this complex case, our technique provided stable fixation of the fragments and a satisfactory final functional outcome.

Non-union coronal fracture femoral condyle, sandwich technique : A case report

Coronal fractures of the femoral condyle (Hoffa fracture) are rare injuries but can be managed with satisfactory outcome if properly treated. We discuss an unusual case of a young adult male presenting with 9 month old neglected Hoffa fracture with pain, stiffness and limitation of knee movement, managed with sandwich bone grafting technique.(1).

Sex-differences of the healthy infra-patellar (Hoffa) fat pad in relation to intermuscular and subcutaneous fat content--data from the Osteoarthritis Initiative

The infra-patellar fat pad (IPFP) is composed of intra-articular adipose tissue; it represents a potential source of pro-inflammatory cytokines and has been associated with osteoarthritis of the knee. Yet, to what extent the size of the IPFP differs between healthy men and women, and how sex differences compare to those in inter-muscular and subcutaneous fat tissue content is unknown. We studied healthy reference subjects from the Osteoarthritis Initiative, without knee pain, without radiographic signs or without risk factors of femorotibial osteoarthritis. Sagittal magnetic resonance images (MRIs) of 99 right knees were used to segment the IPFP; in a subset, axial images of the thigh were available to segment inter-muscular and subcutaneous fat. Healthy men (n=40) displayed a 41% greater (p<0.001) IPFP volume and a 9% greater (p<0.01) ratio of IPFP volume/body weight than women (n=59). Men (n=13) displayed 15% greater intermuscular fat content (not significant), and a 50% lesser (p<0.01) subcutaneous fat content than women (n=12); when related to total thigh cross-sectional areas, these sex differences were +2% (not significant) and -53% (p<0.001). This is the first study to explore quantitative measures of the IPFP in healthy men and women, and to relate these to sex differences of inter-muscular and subcutaneous fat tissue content. Men displayed a significantly greater ratio of IPFP volume/body weight than women, similar amounts of inter-muscular fat, and strikingly less subcutaneous fat. These data provide a basis for further systematic studies of the variability of the IPFP with the body mass index and its role in knee osteoarthritis.

A rare case of unicondylar medial Hoffa fracture associated with ipsilateral vertical patella fracture

An 18 year old male patient was hit by a car to his motorcycle causing a unicondylar Hoffa fracture and an ipsilateral patella fracture. Hoffa fracture is a rare lesion and this association of injury has not been reported before.

Hoffa fracture: fixation using headless compression screws

INTRODUCTION

Hoffa fractures are uni- or bicondylar fractures of the distal femur in a coronal tangential plane.

CASE PRESENTATION

We report the case of an isolated, low energy, closed, displaced, lateral femoral condyle Hoffa fracture in a 54 year old Caucasian man. This was treated by open reduction and internal fixation using two headless compression screws. At 1 year review the patient was pain free, the fracture had radiographically united and there was a range of movement to his knee of 0°-100°.

DISCUSSION

Traditional methods of fixation for Hoffa fractures have led either to the application of complicated constructs attempting to achieve stability, or to large articular surface defects created whilst countersinking headed lag screws. Both have negative implications for the patient. We describe a novel method, not previously described in the literature, using screws in a posterior to anterior direction. This provides compression perpendicular to the fracture site whilst protecting against shear and torsional forces, thereby providing more stable fixation. Furthermore, our method allows for a minimally invasive approach and uses headless compression screws, which reduces the chance of damage to the articular surface and is, therefore, less physiologically invasive.