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Arthroscopic Management of a Posterior Femoral Condyle (Hoffa) Fracture: Surgical Technique
Arthroscopic Management of a Posterior Femoral Condyle (Hoffa) Fracture: Surgical Technique Ahmad M. Wagih, M.D., M.R.C.S., F.E.O.B.
Abstract: Unicondylar fractures of the lower end of the femur are uncommon injuries that usually occur in the sagittal plane. A coronal (tangential) plane fracture, first described by Hoffa in 1904, is unusual. It is an intrinsically unstable type of intra-articular fracture that warrants operative fixation, usually by an open technique. A simple method for the treatment of lateral femoral condyle coronal fractures with arthroscopic-assisted reduction and internal fixation by cannulated screws is reported. Managing fractures of the posterior femoral condyle with arthroscopic reduction and fixation with cannulated screws is simple and effective and could be reproducible with good results and a good prognosis.
A
n isolated coronal fracture of either or both femoral condyles is an unusual injury. First mentioned by Friedrich Busch in 1869, this fracture was later named after Albert Hoffa in 1904.1 The mechanism of injury is axial compression to the knee with transmission of the ground reaction force through the tibial plateau to the femoral condyles. In a flexed position, the posterior portion of the lateral condyle is the one receiving the first impact. Although Hoffa fractures can occur in either femoral condyle, this positioning makes them more common on the lateral side.2 Because this kind of fracture pattern is exposed to continual shear stresses in both the coronal (varus/ valgus) and sagittal (flexion/extension) planes, it is an intrinsically unstable type of intra-articular fracture that warrants operative fixation. Indeed, cases of malunion and nonunion have been reported when Hoffa fractures have not been managed surgically.3 A technique for managing a fracture of the posterior lateral femoral condyle (Hoffa fracture) is reported with arthroscopic reduction and fixation with cannulated screws. The technique showed very good results as a minimally invasive method to deal with this fracture.
From the Department of Orthopaedic Surgery, National Institute of Neuromotor System, Cairo, Egypt. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received November 24, 2014; accepted March 5, 2015. Address correspondence to Ahmad M. Wagih, M.D., M.R.C.S., F.E.O.B., Department of Orthopaedic Surgery, National Institute of Neuromotor System, Kornish Imbabah, Giza, Cairo, Egypt. E-mail: [email protected] Ó 2015 by the Arthroscopy Association of North America 2212-6287/14986/$36.00 http://dx.doi.org/10.1016/j.eats.2015.03.005
Surgical Technique The patient’s history and clinical examination findings show that the knee has sustained a direct or indirect injury with tense hemarthrosis. Usually, the radiographs show a suspicious abnormality of the lateral femoral condyle especially on the lateral view (Fig 1). Computed tomography is requested to confirm a fracture of the lateral femoral condyle in the coronal plane (Fig 2). Examination under anesthesia shows significant valgus instability in 30 of flexion and none in extension. The patient is put in a supine position under general or local anesthesia, and a tourniquet is applied over the left thigh with the leg resting on the surgeon’s thigh over the side of the operating table. Diagnostic arthroscopy (Video 1) with lavage and evacuation of hemarthrosis is performed with a motorized shaver. Viewing is performed through the anterolateral portal, and working instruments are placed through the anteromedial portal. Exposure of the fracture edges shows the fractured posterior lateral femoral condyle (Fig 3A). The tibial surface, menisci, and cruciate ligaments are examined for any associated injuries. The displaced condylar fragment is attached to the posterior capsule. Flexing the knee to 120 while resting the foot on the surgeon’s thigh relaxes the posterior capsule and gastrocnemius and helps achieve reduction of the fracture with the aid of a curved artery forceps (Fig 3B). The fracture is displaced posteriorly, and with hyperflexion of the knee, the tibial plateau pushes the fragment back into place. The condyle is reduced and temporarily stabilized with 2 percutaneous guidewires inserted in an oblique direction, aiming medially and anteriorly from the most
Arthroscopy Techniques, Vol 4, No 4 (August), 2015: pp e299-e303
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Fig 1. Anteroposterior and lateral radiographic views of left knee.
lateral and posterior aspect of the fragment, just above the lateral meniscus. The guidewires are drilled after measurement of the depth, and the fracture is fixed with two 6.5-mm partially threaded cancellous lag screws (Fig 4). A minimum of 2 screws is mandatory to provide rotational stability.4 The screw heads through the articular cartilage are countersunk (Fig 5). The reduction and the alignment of the screws are confirmed by intraoperative fluoroscopy. Before portal closure, testing with knee flexion up to 135 is performed to ensure that satisfactory stability has been achieved. No blood loss is encountered, and the surgical duration is approximately 30 minutes. Tips and pearls for this technique are summarized in Table 1.
Postoperatively, after radiographs are taken (Fig 6), noneweight-bearing ambulation is permitted on the same day of surgery. Range-of-motion exercises are delayed for 3 weeks in a hinged knee brace, but quadriceps drill and straight legeraising exercises are encouraged immediately. Gradually, within 6 weeks, a full range of knee movement is regained (Fig 7). After 12 weeks, follow-up radiographs are taken and full weight bearing is allowed.
Discussion The management goal for all types of intra-articular fractures is to achieve anatomic reduction and adequate stability enabling early mobilization. It is
Fig 2. Computed tomography scans in sagittal and axial planes of left knee.
POSTERIOR FEMORAL CONDYLAR FRACTURE
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Fig 3. Views from anterolateral portal. (A) Exposure of the fracture edges shows the fractured posterior lateral femoral condyle. (B) Reduction of the fracture with the aid of a curved artery forceps from the anteromedial portal.
Fig 4. (A) The condyle is reduced and temporarily stabilized with 2 percutaneous guidewires, inserted from the most lateral and posterior part of the fragment, just above the meniscus. (B) The guidewires are drilled after measurement of the depth.
Fig 5. (A) The fracture is fixed using two 6.5-mm partially threaded cancellous lag screws. (B) The screw heads through the articular cartilage are countersunk.
generally accepted that operative fixation of Hoffa fractures is necessary to achieve this goal. The rarity and peculiar anatomic location of Hoffa fractures render their management a challenge.5 Injury occurs as the result of a violent force and generally occurs in young adults. The fracture results Table 1. Tips and Pearls Reduction of the fragment is performed with a curved hemostat and hyperflexion of the knee. The fragment is fixed by 2 guidewires first, before insertion of the screws, to prevent any displacement during tightening. The direction of the screws should be as anterior and medial as possible from the most lateral and posterior part of the fragment, just above the meniscus.
from a combination of forces, including direct trauma, possibly with an element of abduction. The ground reaction force is transmitted through the tibial plateau. Axial compression on a flexed knee concentrates the force in the posterior half of the femoral condyles. In flexion the lateral condyle is the leading part of the knee to receive the impact. Although a Hoffa fracture may occur in either condyle, the preponderance of lateral condylar fractures suggests an anatomic-biomechanical vulnerability due to physiological valgus.6 In Hoffa fractures the fragment is continually exposed to physiological shearing stresses in the sagittal plane during normal flexion/extension. Varus/valgus stress also exists in the coronal plane even though the collateral ligaments are intact, as in the described case.3 The lag
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A. M. WAGIH
Fig 6. Postoperative anteroposterior and lateral radiographic views of left knee.
screws can only provide interfragmentary compression. To buttress the fragment against the shearing force, screws should be applied on the posterior aspect just above the fragment to stop it from superiorly migrating or a buttress locked plate (Synthes, Oberdorf, Switzerland) should be used.7 Such treatment is difficult and almost infeasible because of limited access when using the lateral parapatellar exposure8dhence the advantage of arthroscopic-assisted reduction and fixation with cannulated screws (Synthes). The displaced condylar fragment is not clearly seen on the lateral radiograph. Thus, when clinical features suggest a fracture of the lower end of the femur and the anteroposterior and lateral radiographs appear normal, a computed tomography scan may be helpful.9 Coronal fractures when undisplaced can be overlooked easily
Fig 7. Postoperative range of motion after 6 weeks.
and tend to displace with conservative treatment.6 With early anatomic restoration of the articular congruity, the joint mechanics are minimally disturbed. Insertion of screws through the articular cartilage in an oblique direction, aiming medially and anteriorly from the lateral and posterior aspect of the fragment, is necessary to achieve the lag effect as much as possible and is better than the opposite direction from anterior to posterior.10 The screws should be placed as far laterally as possible with their heads countersunk to avoid damage to the opposing articular cartilage.11 Although the direction of the screws is not perpendicular to the fracture and may cause some displacement with tightening, this concern is overcome by first fixing the fracture with 2 guidewires before drilling and inserting the screws. The stable fixation allows for early and pain-free mobilization, reducing the risk of knee stiffness. As for rehabilitation, there is always a conflict between fracture-site stability and early mobilization. Stability of the fracture must be tested intraoperatively with knee range of motion. This reproduces the physiological stresses and shows any fracture motion that could happen during physical rehabilitation. In cases of doubt, Lewis et al.3 recommended plaster immobilization in full extension for 6 weeks because, in such a position, the posterior joint capsule is tightened to provide splinting to the condylar fragment, and any axial loading can be borne by the anterior portion of the condyles. Besides slowing down the rehabilitation program, a shorter follow-up interval, every 1 to 2 weeks, is necessary, and the clinician must remain vigilant and investigate any unexplained increase in pain or swelling during the course of rehabilitation.
POSTERIOR FEMORAL CONDYLAR FRACTURE
Conclusion Managing fractures of the posterior femoral condyle with arthroscopic reduction and fixation with cannulated screws is simple and effective and could be reproducible with good results and a good prognosis.
References 1. Hoffa A. Lehrbuch der Frakturen and Luxationen. Ed 4. Stuttgart: Ferdinand Enke-Verlag, 1904;453. 2. Nork SE, Segina DN, Aflatoon K, et al. The association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures. J Bone Joint Surg Am 2005;87:564-569. 3. Lewis SL, Pozo JL, Muirhead-Allwood WF. Coronal fractures of the lateral femoral condyle. J Bone Joint Surg Br 1989;71:118-120. 4. Ostermann PAW, Neumann K, Ekkernkamp A, Muhr G. Long-term results of unicondylar fractures of the femur. J Orthop Trauma 1994;8:142-146. 5. Neer CS II, Grantham SA, Shelton ML. Supracondylar fracture of the adult femur. A study on one hundred and ten cases. J Bone Joint Surg Am 1967;49:591-613.
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6. Karim A, Rossiter N. Isolated medial unicondylar Hoffa fracture following traumatic knee dislocation. Injury Extra 2006;37:12-14. 7. Shi J, Tao J, Zhou Z, Gao M. Surgical treatment of lateral Hoffa fracture with a locking plate through the lateral approach. Eur J Orthop Surg Traumatol 2014;24: 587-592. 8. Arastu MH, Kokke MC, Duffy PJ, Korley RE, Buckley RE. Coronal plane partial articular fractures of the distal femoral condyle: Current concepts in management. Bone Joint J 2013;95-B:1165-1171. 9. Allmann KH, Altehoefer C, Wildanger G, et al. Hoffa fracturedA radiologic diagnostic approach. J Belge Radiol 1996;79:201-202. 10. Jarit GJ, Kummer FJ, Gibber MJ, Egol KA. A mechanical evaluation of two fixation methods using cancellous screws for coronal fractures of the lateral condyle of the distal femur (OTA type 33B). J Orthop Trauma 2006;20: 273-276. 11. Papadopoulos AX, Panagopoulos A, Karageorgos A, Tyllianakis M. Operative treatment of unilateral bicondylar Hoffa fractures. J Orthop Trauma 2004;18: 119-122.
Abstract: Unicondylar fractures of the lower end of the femur are uncommon injuries that usually occur in the sagittal plane. A coronal (tangential) plane fracture, first described by Hoffa in 1904, is unusual. It is an intrinsically unstable type of intra-articular fracture that warrants operative fixation, usually by an open technique. A simple method for the treatment of lateral femoral condyle coronal fractures with arthroscopic-assisted reduction and internal fixation by cannulated screws is reported. Managing fractures of the posterior femoral condyle with arthroscopic reduction and fixation with cannulated screws is simple and effective and could be reproducible with good results and a good prognosis.
A
n isolated coronal fracture of either or both femoral condyles is an unusual injury. First mentioned by Friedrich Busch in 1869, this fracture was later named after Albert Hoffa in 1904.1 The mechanism of injury is axial compression to the knee with transmission of the ground reaction force through the tibial plateau to the femoral condyles. In a flexed position, the posterior portion of the lateral condyle is the one receiving the first impact. Although Hoffa fractures can occur in either femoral condyle, this positioning makes them more common on the lateral side.2 Because this kind of fracture pattern is exposed to continual shear stresses in both the coronal (varus/ valgus) and sagittal (flexion/extension) planes, it is an intrinsically unstable type of intra-articular fracture that warrants operative fixation. Indeed, cases of malunion and nonunion have been reported when Hoffa fractures have not been managed surgically.3 A technique for managing a fracture of the posterior lateral femoral condyle (Hoffa fracture) is reported with arthroscopic reduction and fixation with cannulated screws. The technique showed very good results as a minimally invasive method to deal with this fracture.
From the Department of Orthopaedic Surgery, National Institute of Neuromotor System, Cairo, Egypt. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received November 24, 2014; accepted March 5, 2015. Address correspondence to Ahmad M. Wagih, M.D., M.R.C.S., F.E.O.B., Department of Orthopaedic Surgery, National Institute of Neuromotor System, Kornish Imbabah, Giza, Cairo, Egypt. E-mail: [email protected] Ó 2015 by the Arthroscopy Association of North America 2212-6287/14986/$36.00 http://dx.doi.org/10.1016/j.eats.2015.03.005
Surgical Technique The patient’s history and clinical examination findings show that the knee has sustained a direct or indirect injury with tense hemarthrosis. Usually, the radiographs show a suspicious abnormality of the lateral femoral condyle especially on the lateral view (Fig 1). Computed tomography is requested to confirm a fracture of the lateral femoral condyle in the coronal plane (Fig 2). Examination under anesthesia shows significant valgus instability in 30 of flexion and none in extension. The patient is put in a supine position under general or local anesthesia, and a tourniquet is applied over the left thigh with the leg resting on the surgeon’s thigh over the side of the operating table. Diagnostic arthroscopy (Video 1) with lavage and evacuation of hemarthrosis is performed with a motorized shaver. Viewing is performed through the anterolateral portal, and working instruments are placed through the anteromedial portal. Exposure of the fracture edges shows the fractured posterior lateral femoral condyle (Fig 3A). The tibial surface, menisci, and cruciate ligaments are examined for any associated injuries. The displaced condylar fragment is attached to the posterior capsule. Flexing the knee to 120 while resting the foot on the surgeon’s thigh relaxes the posterior capsule and gastrocnemius and helps achieve reduction of the fracture with the aid of a curved artery forceps (Fig 3B). The fracture is displaced posteriorly, and with hyperflexion of the knee, the tibial plateau pushes the fragment back into place. The condyle is reduced and temporarily stabilized with 2 percutaneous guidewires inserted in an oblique direction, aiming medially and anteriorly from the most
Arthroscopy Techniques, Vol 4, No 4 (August), 2015: pp e299-e303
e299
e300
A. M. WAGIH
Fig 1. Anteroposterior and lateral radiographic views of left knee.
lateral and posterior aspect of the fragment, just above the lateral meniscus. The guidewires are drilled after measurement of the depth, and the fracture is fixed with two 6.5-mm partially threaded cancellous lag screws (Fig 4). A minimum of 2 screws is mandatory to provide rotational stability.4 The screw heads through the articular cartilage are countersunk (Fig 5). The reduction and the alignment of the screws are confirmed by intraoperative fluoroscopy. Before portal closure, testing with knee flexion up to 135 is performed to ensure that satisfactory stability has been achieved. No blood loss is encountered, and the surgical duration is approximately 30 minutes. Tips and pearls for this technique are summarized in Table 1.
Postoperatively, after radiographs are taken (Fig 6), noneweight-bearing ambulation is permitted on the same day of surgery. Range-of-motion exercises are delayed for 3 weeks in a hinged knee brace, but quadriceps drill and straight legeraising exercises are encouraged immediately. Gradually, within 6 weeks, a full range of knee movement is regained (Fig 7). After 12 weeks, follow-up radiographs are taken and full weight bearing is allowed.
Discussion The management goal for all types of intra-articular fractures is to achieve anatomic reduction and adequate stability enabling early mobilization. It is
Fig 2. Computed tomography scans in sagittal and axial planes of left knee.
POSTERIOR FEMORAL CONDYLAR FRACTURE
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Fig 3. Views from anterolateral portal. (A) Exposure of the fracture edges shows the fractured posterior lateral femoral condyle. (B) Reduction of the fracture with the aid of a curved artery forceps from the anteromedial portal.
Fig 4. (A) The condyle is reduced and temporarily stabilized with 2 percutaneous guidewires, inserted from the most lateral and posterior part of the fragment, just above the meniscus. (B) The guidewires are drilled after measurement of the depth.
Fig 5. (A) The fracture is fixed using two 6.5-mm partially threaded cancellous lag screws. (B) The screw heads through the articular cartilage are countersunk.
generally accepted that operative fixation of Hoffa fractures is necessary to achieve this goal. The rarity and peculiar anatomic location of Hoffa fractures render their management a challenge.5 Injury occurs as the result of a violent force and generally occurs in young adults. The fracture results Table 1. Tips and Pearls Reduction of the fragment is performed with a curved hemostat and hyperflexion of the knee. The fragment is fixed by 2 guidewires first, before insertion of the screws, to prevent any displacement during tightening. The direction of the screws should be as anterior and medial as possible from the most lateral and posterior part of the fragment, just above the meniscus.
from a combination of forces, including direct trauma, possibly with an element of abduction. The ground reaction force is transmitted through the tibial plateau. Axial compression on a flexed knee concentrates the force in the posterior half of the femoral condyles. In flexion the lateral condyle is the leading part of the knee to receive the impact. Although a Hoffa fracture may occur in either condyle, the preponderance of lateral condylar fractures suggests an anatomic-biomechanical vulnerability due to physiological valgus.6 In Hoffa fractures the fragment is continually exposed to physiological shearing stresses in the sagittal plane during normal flexion/extension. Varus/valgus stress also exists in the coronal plane even though the collateral ligaments are intact, as in the described case.3 The lag
e302
A. M. WAGIH
Fig 6. Postoperative anteroposterior and lateral radiographic views of left knee.
screws can only provide interfragmentary compression. To buttress the fragment against the shearing force, screws should be applied on the posterior aspect just above the fragment to stop it from superiorly migrating or a buttress locked plate (Synthes, Oberdorf, Switzerland) should be used.7 Such treatment is difficult and almost infeasible because of limited access when using the lateral parapatellar exposure8dhence the advantage of arthroscopic-assisted reduction and fixation with cannulated screws (Synthes). The displaced condylar fragment is not clearly seen on the lateral radiograph. Thus, when clinical features suggest a fracture of the lower end of the femur and the anteroposterior and lateral radiographs appear normal, a computed tomography scan may be helpful.9 Coronal fractures when undisplaced can be overlooked easily
Fig 7. Postoperative range of motion after 6 weeks.
and tend to displace with conservative treatment.6 With early anatomic restoration of the articular congruity, the joint mechanics are minimally disturbed. Insertion of screws through the articular cartilage in an oblique direction, aiming medially and anteriorly from the lateral and posterior aspect of the fragment, is necessary to achieve the lag effect as much as possible and is better than the opposite direction from anterior to posterior.10 The screws should be placed as far laterally as possible with their heads countersunk to avoid damage to the opposing articular cartilage.11 Although the direction of the screws is not perpendicular to the fracture and may cause some displacement with tightening, this concern is overcome by first fixing the fracture with 2 guidewires before drilling and inserting the screws. The stable fixation allows for early and pain-free mobilization, reducing the risk of knee stiffness. As for rehabilitation, there is always a conflict between fracture-site stability and early mobilization. Stability of the fracture must be tested intraoperatively with knee range of motion. This reproduces the physiological stresses and shows any fracture motion that could happen during physical rehabilitation. In cases of doubt, Lewis et al.3 recommended plaster immobilization in full extension for 6 weeks because, in such a position, the posterior joint capsule is tightened to provide splinting to the condylar fragment, and any axial loading can be borne by the anterior portion of the condyles. Besides slowing down the rehabilitation program, a shorter follow-up interval, every 1 to 2 weeks, is necessary, and the clinician must remain vigilant and investigate any unexplained increase in pain or swelling during the course of rehabilitation.
POSTERIOR FEMORAL CONDYLAR FRACTURE
Conclusion Managing fractures of the posterior femoral condyle with arthroscopic reduction and fixation with cannulated screws is simple and effective and could be reproducible with good results and a good prognosis.
References 1. Hoffa A. Lehrbuch der Frakturen and Luxationen. Ed 4. Stuttgart: Ferdinand Enke-Verlag, 1904;453. 2. Nork SE, Segina DN, Aflatoon K, et al. The association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures. J Bone Joint Surg Am 2005;87:564-569. 3. Lewis SL, Pozo JL, Muirhead-Allwood WF. Coronal fractures of the lateral femoral condyle. J Bone Joint Surg Br 1989;71:118-120. 4. Ostermann PAW, Neumann K, Ekkernkamp A, Muhr G. Long-term results of unicondylar fractures of the femur. J Orthop Trauma 1994;8:142-146. 5. Neer CS II, Grantham SA, Shelton ML. Supracondylar fracture of the adult femur. A study on one hundred and ten cases. J Bone Joint Surg Am 1967;49:591-613.
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6. Karim A, Rossiter N. Isolated medial unicondylar Hoffa fracture following traumatic knee dislocation. Injury Extra 2006;37:12-14. 7. Shi J, Tao J, Zhou Z, Gao M. Surgical treatment of lateral Hoffa fracture with a locking plate through the lateral approach. Eur J Orthop Surg Traumatol 2014;24: 587-592. 8. Arastu MH, Kokke MC, Duffy PJ, Korley RE, Buckley RE. Coronal plane partial articular fractures of the distal femoral condyle: Current concepts in management. Bone Joint J 2013;95-B:1165-1171. 9. Allmann KH, Altehoefer C, Wildanger G, et al. Hoffa fracturedA radiologic diagnostic approach. J Belge Radiol 1996;79:201-202. 10. Jarit GJ, Kummer FJ, Gibber MJ, Egol KA. A mechanical evaluation of two fixation methods using cancellous screws for coronal fractures of the lateral condyle of the distal femur (OTA type 33B). J Orthop Trauma 2006;20: 273-276. 11. Papadopoulos AX, Panagopoulos A, Karageorgos A, Tyllianakis M. Operative treatment of unilateral bicondylar Hoffa fractures. J Orthop Trauma 2004;18: 119-122.