How to determine the surgical approach in Hoffa fractures?

Fragment size of lateral Hoffa fractures determines screw fixation trajectory: a human cadaveric cohort study

BACKGROUND AND PURPOSE

Recommendations regarding fragment-size-dependent screw fixation trajectory for coronal plane fractures of the posterior femoral condyles (Hoffa fractures) are lacking. The aim of this study was to compare the biomechanical properties of anteroposterior (AP) and crossed posteroanterior (PA) screw fixations across differently sized Hoffa fractures on human cadaveric femora.

PATIENTS AND METHODS

4 different sizes of lateral Hoffa fractures (n = 12 x 4) were created in 48 distal human femora according to the Letenneur classification: (i) type I, (ii) type IIa, (ii) type IIb, and (iv) type IIc. Based on bone mineral density (BMD), specimens were assigned to the 4 fracture clusters and each cluster was further assigned to fixation with either AP (n = 6) or crossed PA screws (n = 6) to ensure homogeneity of BMD values and comparability between the different test conditions. All specimens were biomechanically tested under progressively increasing cyclic loading until failure, capturing the interfragmentary movements via motion tracking.

RESULTS

For Letenneur type I fractures, kilocycles to failure (mean difference [∆] 2.1, 95% confidence interval [CI] -1.3 to 5.5), failure load (∆ 105 N, CI -83 to 293), axial displacement (∆ 0.3 mm, CI -0.8 to 1.3), and fragment rotation (∆ 0.5°, CI -3.2 to 2.1) over 5.0 kilocycles did not differ significantly between the 2 screw trajectories. For each separate subtype of Letenneur type II fractures, fixation with crossed PA screws resulted in significantly higher kilocycles to failure (∆ 6.7, CI 3.3-10.1 to ∆ 8.9, CI 5.5-12.3) and failure load (∆ 275 N, CI 87-463 to ∆ 438, CI 250-626), as well as, less axial displacement from 3.0 kilocycles onwards (∆ 0.4°, CI 0.03-0.7 to ∆ 0.5°, CI 0.01-0.9) compared with AP screw fixation.

CONCLUSION

Irrespective of the size of Letenneur type II fractures, crossed PA screw fixation provided greater biomechanical stability than AP-configured screws, whereas both screw fixation techniques demonstrated comparable biomechanical competence for Letenneur type I fractures. Fragment-size-dependent treatment strategies might be helpful to determine not only the screw configuration but also the surgical approach.

Exposure of Hoffa Fractures Is Improved by Posterolateral and Posteromedial Extensile Approaches: A Qualitative and Quantitative Anatomical Study

BACKGROUND

The current literature lacks recommendations regarding surgical approaches to best visualize and reduce Hoffa fractures. The aims of this study were to (1) define surgical corridors to the posterior portions of the lateral and medial femoral condyles and (2) compare the articular surface areas visible with different approaches.

METHODS

Eight fresh-frozen human cadaveric knees (6 male and 2 female donors; mean age, 68.2 ± 10.2 years) underwent dissection simulating 6 surgical approaches to the distal femur. The visible articular surface areas for each approach were marked using an electrocautery device and subsequently analyzed using image-processing software. The labeled areas of each femoral condyle were statistically compared.

RESULTS

At 30° of flexion, visualization of the posterior portions of the lateral and medial femoral condyles was not possible by lateral and medial parapatellar approaches, as only the anterior 29.4% ± 2.1% of the lateral femoral condyle and 25.6% ± 2.8% of the medial condyle were exposed. Visualization of the lateral femoral condyle was limited by the posterolateral ligamentous structures, hence a posterolateral approach only exposed its central (13.1% ± 1.3%) and posterior (12.4% ± 1.1%) portions. Posterolateral extension by an osteotomy of the lateral femoral epicondyle significantly improved the exposure to 53.4% ± 2.7% and, when combined with a Gerdy's tubercle osteotomy, to 70.9% ± 4.1% (p < 0.001). For the posteromedial approach, an arthrotomy between the anteromedial retinaculum and the superficial medial collateral ligament, and one between the posterior oblique ligament and the medial gastrocnemius tendon, allowed visualization of the central (13.5% ± 2.2%) and the posterior (14.6% ± 2.3%) portions of the medial femoral condyle, while a medial femoral epicondyle osteotomy significantly improved visualization to 66.1% ± 5.5% (p < 0.001).

CONCLUSIONS

Visualization of the posterior portions of the femoral condyles is limited by the specific anatomy of each surgical corridor. Extension by osteotomy of the femoral epicondyles and Gerdy's tubercle significantly improved articular surface exposure of the femoral condyles.

CLINICAL RELEVANCE

Knowledge of the surgical approach-specific visualization of the articular surface of the femoral condyles might be helpful to properly reduce small Hoffa fragments.

Subvastus Arthrotomy and Multifaceted Fixation in Medial Femoral Comminuted Hoffa's Fracture: A Case Report

In managing orthopedic trauma, Hoffa's fracture, a rare intra-articular fracture affecting the femoral condyle, presents a unique challenge. We report a case of a 45-year-old male patient who had a traumatic injury and complained of substantial knee discomfort and limited range of motion. The patient had a medial femoral comminuted Hoffa's fracture. Subvastus arthrotomy was employed to handle the fracture successfully, and then a locking reconstruction plate, Herbert screws, and 4 mm cannulated screws were used for precise reduction and fixation. At the one-year follow-up, the patient showed acceptable postoperative results, including recovered knee function and radiographic indications of fracture repair.

Biomechanics of internal fixation in Hoffa fractures - A comparison of four different constructs

OBJECTIVE

Compare the biomechanical effectiveness of four different bone-implant constructs in preventing fracture displacement under axial loading.

METHODS

Twenty artificial femora had a standardized coronally oriented fracture of the lateral femoral condyle, representing a Hoffa fracture classified as a Letenneur type I. Four different fixation constructs were applied to the synthetic bones for biomechanical testing. The constructs consisted of a posterolateral (PL) buttressing locking plate in conjunction with two cannulated lag screws inserted from posterior to anterior (PA) - Group 1; Two cannulated screws inserted from anterior to posterior (AP) without plating- Group 2; A posterolateral (PL) buttressing locking plate in isolation - Group 3; and a combination of two lag screws from anterior to posterior (AP) in addition to a horizontal one-third tubular locking plate - Group 4. An axial load was applied to the fracture site with a constant displacement speed of 20 mm/min, and the test was interrupted when a secondary displacement was detected determining a fixation failure. We recorded the maximum applied force and the maximum fracture displacement values.

RESULTS

Group 1 demonstrated the highest overall bone-implant axial stiffness with the lowest secondary displacement under loading. Groups 3 and 4 showed equivalent mechanical behavior. Group 2 presented the lowest mechanical stiffness to axial loading. The combination of the one-third tubular locking plate with anterior-to-posterior lag screws (Group 4) resulted in 302 % increase in fixation stiffness when compared to anterior-to-posterior lag screws only (Group 2).

CONCLUSIONS

This study confirms the mechanical superiority of having a plate applied parallel to the main fracture plane in the setting of coronally oriented femoral condyle fractures. The addition of a horizontal plate, perpendicular to the main fracture plane, significantly increased the resistance to shearing forces at the fracture site when compared to constructs adopting just cannulated screws.

LEVEL OF EVIDENCE

Biomechanical study.

Combined approach in the treatment of comminuted lateral Hoffa fracture: a case report

Coronal-plane intra-articular fractures of the femoral condyle (Hoffa fractures) are rare, and difficult to diagnose and treat. They mostly result as a consequence of high-energy trauma and are combined with concomitant fractures (patellar, tibia shaft) and/or soft-tissue damage. A plain X-ray can miss the diagnosis initially and therefore computerized tomography scan is recommended, which can also help in the preoperative planning. The vast majority of these fractures are unicondylar (mostly lateral condyle fractured). The approach for their treatment can be anterior or posterior. In cases of fracture comminution, much more mutilant approaches with osteotomy have been described. A combined two-stage approach can be used to obtain anatomical reduction and fixation of all the fragments. We present a case of a 46-year-old male patient with comminuted lateral Hoffa fracture treated with a combined approach (extended posterior approach to the proximal tibia and lateral parapatellar) in a time interval of one month.

Busch-Hoffa fracture: A systematic review

BACKGROUND

Accomplish a thorough review on the existing biomechanical and clinical studies about coronal plane fractures of the distal femur.

METHODS

We performed an electronic search of PubMed/MEDLINE database from April to June, 2023. The terms for the database search included "Hoffa fractures," OR "Busch-Hoffa fractures" OR "coronal plane fractures of the distal femur."

RESULTS

The search identified 277 potentially eligible studies. After application of inclusion and exclusion criteria, 113 articles were analyzed in terms of the most important topics related to coronal plane fractures of the distal femur.

CONCLUSION

Lateral coronal plane fractures of the distal femur are more frequent than medial, present a more vertical fracture line, and usually concentrate on the weight bearing zone of the condyle. The Letenneur system is the most used classification method for this fracture pattern. Posterior-to-anterior fixation using isolated lag screws (for osteochondral fragments-Letenneur type 2) or associated with a posterior buttressing plate (when the fracture pattern is amenable for plate fixation-Letenneur types 1 and 3) is biomechanically more efficient than anterior-to-posterior fixation. Anterior-to-posterior fixation using lag screws complemented or not by a plate remains a widely used treatment option due to the surgeons' familiarity with the anterior approaches and lower risk of iatrogenic neurovascular injuries. There is no consensus in the literature regarding diameter and number of screws for fixation of coronal plane fractures of the distal femur.

Application of the suture anchor in the treatment of Hoffa fractures of the lateral femoral condyle

BACKGROUND

To evaluate the feasibility and clinical effect of the suture anchor combined with external fixation in the treatment of the lateral femoral condyle Hoffa fracture.

METHODS

In this study, a retrospective study was conducted to analyze the feasibility of treating fourteen patients (eight men and six women) with Hoffa fractures admitted to our Hospital from January 2016 to October 2021 with combined external fixation using incisional reduction anchor nailing. The age of the patients ranged from 23 to 45 years, with an average of 37.5 years. According to Letenneur's classification, there were eight cases of type I, three cases of type II, and three cases of type III. The functional assessment of Letenneur was used to measure the clinical outcome.

RESULTS

All patients had one-stage wound healing, and all patients were followed up for 12 to 18 months after surgery, and all fractures healed well, with normal knee flexion and extension activities, and no complications such as fracture displacement, anchor nail loosening, or fracture malunion were observed. The clinical outcome was evaluated according to the functional evaluation criteria of Letenneur et al. The clinical outcome of fourteen patients: excellent in thirteen cases and good in one case, with an overall excellent rate of 100%.

CONCLUSIONS

Our study results indicate that the use of anchor nailing combined with external fixation for Hoffa fractures of the femoral condyle has some clinical reference significance because it is less invasive, has fewer complications, does not require secondary removal, and is worthy of clinical application.

TRIAL REGISTRATION

Retrospectively registered.

Double plating via anterolateral and posterolateral approach for distal femoral fracture

Although there are some reports highlighting the applicability of double plates in distal femoral fractures, there is no standard approach or fixation method for supracondylar fractures combined with posterior coronal shear fractures. We report a case of distal femoral fracture treated with a lateral locking plate and posterior buttress plate using anterolateral and posterolateral approaches from one incision. A 70-year-old man was hit by a motorcycle and had an intra-articular distal femoral fracture involving a long medial proximal spike and a single lateral condyle fragment, with the lateral condyle fragment posteriorly displaced. A 12-cm lateral skin incision was made, and the joint was developed using a para-patellar approach from the anterior to iliotibial band. Posterior buttress plate fixation was successfully performed from behind the iliotibial band using a posterolateral approach, followed by cannulated cancellous screw and lateral locking plate fixation from the anterolateral window. Combined anterolateral and posterolateral approaches from one incision enable intra-articular exposure and fixation based on fixation principles for lateral condyle fragments combined with supracondylar fracture.

Non-Union of Isolated Medial Condyle of Femur Hoffa Fracture: Case Report

Isolated non-united Hoffa fracture of the femur is a rare finding. They are often missed due to the nature of the fracture and when not assessed appropriately. This is a case report of a 40-year-old male who encountered a high-velocity trauma; the fracture was probably missed on plain radiographs following the trauma. The patient presented to us eight months following the trauma with complaints of pain and decreased range of motion of his right knee (10 to 80 degrees of flexion) and the patient was unable to bear weight on the affected limb. On evaluation, the patient was found to have a non-united Hoffa fracture involving the medial condyle. The patient was treated with freshening of fracture followed by rigid fixation with cancellous screws and reconstruction plate. Postoperatively by week six, the patient achieved full range of motion and was able to walk without assistance with evidence of union on plain radiographs.

Treatment of Hoffa fracture of femoral condyle with anchor combined with auxiliary fixation

BACKGROUND

A Hoffa fracture is an unstable intra-articular break that is generally treated with surgery.

OBJECTIVE

To evaluate the feasibility and clinical outcomes of using a suture anchor combined with auxiliary fixation for the treatment of a lateral femoral condyle Hoffa fracture.

METHODS

The study retrospectively reviewed 8 patients (5 males and 3 females) with a lateral femoral condyle Hoffa fracture who had been treated by combining a suture anchor with auxiliary fixation between January 2016 and April 2020. The mean age of patients was 37.5 years (ranging from 23 to 45). According to Letenneur's classification, there were 4 cases of type I, 2 cases of type II, and 2 cases of type III fractures. The clinical outcomes were assessed using Letenneur's functional assessment.

RESULTS

The follow-up duration ranged between 14-24 months. All patients achieved primary healing of the incision and fracture union, as well as normal flexion and extension of the knee joint, with 7 cases showing excellent outcomes and 1 case showing a good outcome. No postoperative complications, such as fracture displacement, anchor loosening, or fracture malunion, occurred in this series.

CONCLUSION

Our results indicated that a suture anchor, combined with external fixation, was an effective treatment for a lateral femoral condyle Hoffa fracture. Accordingly, this procedure is worthy of wider clinical application.

A case report of the Hoffa fracture and a review of literature

The Hoffa fracture is an uncommon fracture. There is a lot of confusion about its diagnosis and management with several conflicting reports in literature. We reported a 25-year-old patient with non-union of Hoffa fracture, and meanwhile tried to develop an algorithm-based treatment for Hoffa fractures. A systematic review of the available literature was performed. Medline, Embase, the Cochrane Library and PubMed were searched for relevant articles. Fifty-five articles were reviewed, and the clinical knowledge base was summarized. The understanding of the mechanism of trauma has become more nuanced. The literature has also evolved to classify the fracture with the purpose of surgical management in mind. This can be used to plan approach and fixation with preservation of blood supply. Classification can also prognosticate the outcomes in Hoffa fracture.

The outcomes of surgical treatment for lateral Hoffa fracture nonunions

INTRODUCTION

Lateral Hoffa nonunion are rare injuries. A significant percentage of these nonunions are due to missed acute lateral Hoffa fractures. Operative management of these injuries is difficult and complicated by the presence of bone loss, infection, and soft-tissue contractures. In this study, the aim was to assess clinical and functional outcome in our group of patients with lateral Hoffa nonunion who had undergone operative management and to determine whether variables such as fracture type, infection, and previous surgery affect nonunion/complication rates.

MATERIALS AND METHODS

Data were analyzed for patients with lateral Hoffa nonunion who underwent surgical fixation from January 2008 to December 2020 at a tertiary-care referral center. Patients with lateral condyle Hoffa nonunion and having a minimal follow-up of 1 year were included in this study. Patients with medial Hoffa nonunion, pathological fractures, and children aged less than 16 years were excluded from the study. The fractures were classified by the AO/OTA and Letenneur classification systems. Clinical and functional outcomes were assessed by the Knee society score (KSS) and the lower extremity functional scale (LEFS).

RESULTS

All the 12 patients had united in our series. One patient had reduction failure at 3 months who united after re-fixation. The union rate in our patients was 100%, with a loss of reduction rate of 7.7%, and post-traumatic arthrosis of 7.7%. The average follow-up period was 52.16 ± 27.7 months. The mean knee flexion obtained at the final follow-up was 104.5° (80°-130°). The average KSS clinical score was 80.6 (65-88). The average KSS functional score was 92 (70-100). The average LEFS score was 71 (47-79). There is a statistically significant improvement in the knee range of motion in our patients (p = 0.001). However, no correlation could be detected between variables like type of fracture, infection, and previous surgeries and outcomes.

CONCLUSIONS

Lateral Hoffa nonunion can be managed with careful planning of surgical approaches and fixation techniques.

Hoffa’s fracture in an adolescent treated with an innovative surgical procedure: A case report

BACKGROUND

Hoffa fracture is rare, especially in adolescents, and has a high rate of complications such as avascular necrosis and osteoarthritis; moreover, there are no definitive guidelines for its treatment. This report could provide a new potential treatment for Hoffa fracture.

CASE SUMMARY

A 16-year-old girl presented to the orthopedic emergency department of No. 2 People’s Hospital of Yibin City with persistent pain following a right knee injury sustained during a sprint race. Her knee was swollen and tender, and the range of motion was restricted by the pain. X-ray and computed tomography revealed a Hoffa fracture in the right knee. After consultation, surgical treatment was performed, and the fracture was fixed with three 3.5-mm cannulated cancellous screws; osteochondral plugs that were harvested from the screw insertion site were re-implanted to cover the screw head. The patient’s fracture and osteochondral plug healed 6 mo postoperatively, and she presented a knee range of motion of 0–135 without pain, and was walking without support with a normal gait.

CONCLUSION

Here, we describe an innovative surgical procedure for Hoffa fracture that could provide a new possibility for the treatment of similar fractures, and further improve their management.

Hoffa fracture combined with rotational dislocation of the knee joint: A novel case report

RATIONALE

Hoffa fracture is a rare fracture confined to the coronal-plane involving femoral condyles. This occurs simultaneously with rotational dislocation of the knee joint is extremely rare. Up to now, there is no valid recommendation for the treatment of the Hoffa fracture.

PATIENT CONCERNS

A 50-year-old female patient broke her knee joint while skiing, experiencing severe pain in the right knee, which was swollen. She presented limited function of the knee and movement upon arrival in the emergency room.

DIAGNOSIS

Comminuted Hoffa fracture in the right knee associated with rotational dislocation in the knee joint.

INTERVENTIONS

We treated the dislocated knee joint through manual reduction initially. During the operation, we used posterolateral approach to expose the fracture fragments, thereafter using headless compression screws and a buttress plate to provide sufficient stability for the fracture. Early postoperative rehabilitation was encouraged.

OUTCOMES

The patient finally achieved fracture healing three months after operation. In addition, she achieved 0-130° range of function of the knee after four months post-operation, and the patient obtained a satisfactory prognosis after our treatment.

LESSONS

By using appropriate surgical approach to obtain enough exposure, headless compression screws and the buttress plate provided adequate stability during early active rehabilitation, which resulted in satisfactory results in the treatment of the injury. We reviewed literatures regarding the treatment of Hoffa fracture to demonstrate that our treatment was effective.

A biomechanical comparison of two screw fixation methods in a Letenneur type I Hoffa fracture

Background

The treatment of Hoffa fractures is challenging, for which the ideal fixation and approach are still controversial. Osteosynthesis with plate or screws fixation in different trajectories have been described in previous literature. The purpose of this study was to compare the biomechanical strength and stability of two types of screw trajectories used to stabilize displaced coronal fractures of the lateral femoral condyle.

Methods

Sixteen synthetic femurs (Sawbones Pacific Research Laboratories, Vashon, WA) were divided into two groups. A vertical osteotomy was performed to mimic a Letenneur type I Hoffa fracture. Group A (n = 8) was fixed with screw in anteroposterior direction (A-P) screws. Group B (n = 8) was fixed with crossed screws. Both groups were tested with a nondestructive axial compression aligned with the femur axis. After that, 10,000 cyclic loading tests were applied to the specimen with a force ranging between 200 to 600 N, and the interfragmental displacement was recorded, respectively, after 10, 100, 1000 and 10,000 cycles. Finally, a destructive axial compression test was applied until catastrophic failure.

Results

There were no statistical between-group differences in regard to the average axial stiffness, interfragmental displacement, and ultimate failure load. The average axial stiffness of the A-P screw was comparable to that of the crossed screw (361 ± 113 N/mm vs. 379 ± 65 N/mm, p = 0.753). All specimens completed the entire cyclic loading test without catastrophic failure, and the interfragmental displacement after loading for 10,000 cycles was 1.36 ± 0.40 mm for the A-P screw and 1.29 ± 0.61 mm for the crossed screw, there were no statistical differences between the groups (p = 0.823). The average ultimate failure loads for the A-P and crossed screws were 1214 ± 127 N and 1109 ± 156 N, respectively (p = 0.172).

Conclusions

Based on our in vitro study, the crossed screws can provide comparable mechanical performance as traditional A-P screws in Hoffa fracture fixation. Considering the screws trajectories are commonly determined by the choice of surgical approach, the current study provides support from a biomechanical perspective for the application of crossed screws in direct lateral approach.